If there's an award for switching between the most careers, Cassandra Grey should prepare her winning speech.

When asked as a child what she wanted to be, she filtered through answers every time: astronaut, cowboy–not cowgirl; she was very adamant about that at four years old–singer, dancer, detective, writer, cheerleader, surgeon, etc. The list went on and on. In defense of her younger self, she actually did quite a few of those: she was a cheerleader in high school and college, where she studied both medicine and criminal justice with a minor in psychology.

Medical school was for her twin sister, Lexie, and since their father was paying for their education, she figured she might as well take as many courses as she could.

Her and Lexie pushed each other to succeed, managing to get their degrees and complete med school in six years. The two of them had always been studious with amazing memories–although Lexie was the only one of the two with a photographic memory–and they encouraged each other every step of the way.

Honestly, by the time they started working in the same hospital as their estranged older sister, Cassandra had accepted that medicine was her path. As exciting as that class Jason Gideon taught on the Behavioral Analysis Unit was, studying medicine was clearly meant to be. For four years she learned to become a trauma surgeon, became close to her older sister Meredith, and rebuilt a life for herself in Seattle after her mother's sudden death a few months before she graduated.

It was perfect, until a plane crash brought her world crashing down around her.

She endured one last year at Seattle Grace Mercy West–or, more accurately, Seattle Grace Mercy Death; Alex Karev had really been onto something when he coined that nickname for the hospital–staying only long enough to become Board certified, in honor of Lexie.

Her brother-in-law, Derek Shepherd, had been the one to recognize how badly she was drowning in the aftermath. He'd shoved her onto a plane–ironic, truly–to New York, where she was able to find a job in a previously dropped career path.

For nearly two years, she worked in the Sexual Victims Unit, helping victims reclaim their lives. There, she was Officer–and later Detective–Cassandra Grey, a dedicated member of the police force. She wasn't known as a member of the Seattle Grace Six, renowned for surviving a freak accident.

She learned to breathe again.

All of that led to now, standing outside of FBI headquarters in Qauntico, Virginia.

After all, the Behavioral Analysis Unit had always been her secret dream.

Unit Chief Aaron Hotchner is curt and to the point.

Cassandra respects that. Honestly, she appreciates it. It's clear that he's not thrilled that she was hired by his boss and not him, but he's professional as he shakes her hand and leads her up to his office, where he gestures to the chair in front of his desk. She takes a perfunctory glance around the room, automatically analyzing him based off of his office before she catches herself.

Hotchner doesn't mention it but she knows that he saw her doing it.

"Sergeant Benson had nothing but positive things to say about you when I called." He tells her, flipping open a file on her. "Only two years in law enforcement . . . how old are you?"

Cassandra doesn't think for a second that he doesn't already know the answer.

"I am 29, sir." Cassandra answers. "I went to med school and became a surgeon before switching careers."

He already knows that, too.

"I see." Hotchner nods, closing the file and setting it to the side. His eyes are piercing, focused only on her now. "What made you switch to law enforcement?"

"I have a doctorate in criminal justice and a bachelors in psychology." She tells him, knowing that he wants the more personal answer. "Agent Gideon was a guest lecturer at Harvard Law and I was fascinated by his explanation of the BAU."

He doesn't push for more information, smiling slightly–the first one she's received so far–as he tells her that Gideon encourages a lot of people to join the BAU.

"Most of them aren't even considered." He tells her. "People would kill to have your opportunity. Don't waste it."

"Of course not." She says, meaning every word. This is her new beginning, and she's going to prove herself to him the first opportunity she gets.

Derek Morgan is the first one to introduce himself when she walks down from Hotchner's office.

It's an open office space with corner desks, all equipped with a desktop computer, phone, and other needed work supplies. There are a handful of agents working and talking to each other, and for a second she just observes, her anxiety rising over being the new girl. She hates not knowing where to go, and she wasn't told any next steps past getting introduced to her new team.

"You look lost." A warm voice nearly has her jumping, and his chuckle fills the air as Cassandra turns to face a beautiful man. He gives her a small grin, a teasing glint in his eye as he holds his hand out for her to shake. His grip is firm, his hands calloused: he's clearly a hands on man. "Supervisory Special Agent Derek Morgan."

"Doctor–um, sorry." Cassandra stumbles, cringing at herself. Two years and she still resorts to a title she doesn't fit anymore. "Special Agent Cassandra Grey. It's a pleasure to meet you."

"Pleasure's all mine." He returns with a wink, looking curious now. "Doctor, huh? You're not the only one. Yo! Pretty Boy!"

The moniker is accurate: the man who lifts his head has the facial structure to be a model. He's wearing a red sweater over top a white button up, and he's got his hair gelled back. He looks young, which is a relief: she'd been worried about working with primarily condescending older agents, but between him and Morgan, she might just be safe.

Derek sets his arm around Cassandra's shoulders, leading her to the desks that his coworker is sitting at. The action doesn't feel overbearing or presumptuous, only friendly, and Cassandra finds herself not minding it. He pulls out a desk chair for her, telling her to make herself comfortable, and she's relieved to not have to ask which desk is hers.

She's now to the left of Morgan and diagonal to the unnamed man, who is staring at her in confusion.

"Did you need something?" He finally asks Morgan, who huffs out a laugh.

"No, kid. I just wanted to tell you that you're not the only smartie pants in the BAU anymore. Grey over here is a doctor too."

His face lights up, a smile forming, and Cassandra is quick to return the look.

"What subject?" He asks her. "Or subjects? Sorry, I shouldn't assume it was only one."

"That's okay." She assures him, not wanting him to feel bad. It's a typical assumption. "I have a PhD in criminal justice, a bachelors in psychology, and was a trauma surgeon for five years. What about you?"

"Mathematics, chemistry, and engineering." He answers promptly. "I also have bachelor degrees in psychology and sociology. Caltech."

"Harvard." Cassandra gives him a grin. "That's very impressive, Doctor . . ."

"Oh! Sorry. Spencer Reid." He introduces himself, flushing while Morgan laughs at the two of them.

"Cassandra Grey. It's great to meet you." Cassandra introduces herself in return, surprised when his eyes widen.

"Grey, as in–?"

Don't say plane crash, don't say plane crash, don't say plane–

"The Grey Method?" He finishes his thought, and Cassandra all but sighs in relief. She'll take a connection to Ellis Grey over anything else.

"Close." She tilts her hand in a so-so method. "Ellis Grey was my older sister's mother, not mine."

"What's the Grey Method?" Morgan asks, and Cassandra opens her mouth to answer, only for Reid to beat her to it.

"The Grey Method is a laparoscopic technique to treat gallbladders created by Ellis Grey during her residency at Seattle Grace Hospital. The method was published in the American Journal of Medicine and earned her a Harper Avery Award in 1988."

"Wow. You . . . know a lot about that." Cassandra says slowly, impressed.

"He knows a lot about a lot." Morgan tells her, idly sorting through his case files. "He's a genius. Eidetic memory."

"Oh, that's–"

"Weird, I know." Reid sighs, sounding as if he's heard that a hundred times. Cassandra frowns, remembering all the times Lexie was teased for her photographic memory–or taken advantage of because of it.

"I was going to say cool, actually." She corrects him gently. "I mean, it has to be exhausting to remember so much, but it's cool that you can add to a conversation like that."

"Oh. Thank you." He says, looking surprised before he abruptly stands up. "Coffee."

Cassandra watches him flee with the sinking feeling that she's managed to ruin that first impression.

"Did I say something, or . . .?" She trails off, looking to Morgan, who just waves her worries away.

"Nah, he's just not . . . the best with human interaction." He explains slowly, shrugging. "You didn't insult him or anything. Don't worry about it. Oh, hey, there's JJ."

'JJ' is short for Jennifer Jareau, the gorgeous blonde media liaison who introduces herself while typing away on her phone, simultaneously emailing while explaining things to Cassandra, who is beyond impressed with her. She leaves as she answers the phone, rolling her eyes in a 'so help me' motion to Morgan as she goes.

Is everyone that works here drop dead gorgeous?

"I think I'm a little bit in love with her." Cassandra states slowly, smiling down at the post-it note JJ had stuck to her desk, scribbling her number on it because 'I'm never in my office, but always near my phone. Call me!' There's a smiley face under it.

"Oh, you'll fit right in, kid." Morgan smiles at her, sliding her one of his files. "Now, look through this and tell me what you notice. That's your first test."

"Is it a test or do you just not want to do your paperwork?" She asks him dryly, getting a smirk in return as he pointedly slides her a few more files from his stack.

Cassandra likes it here already.

Morgan promises to show her around but they don't get the chance, a case coming in that sends them straight up to their case room while Reid is sent to recruit Jason Gideon from where he's currently lecturing at a college. Morgan tenses up as soon as Gideon's name is mentioned, clearly uncomfortable, and Cassandra is fairly certain it's due to the recent bombing. Gideon had sent six agents into a trap, killing them all, and has been absent from the BAU ever since.

JJ is the one to bring the case to them, and she sends Cassandra an amused look as she hands her a file.

"I hope you miss Seattle." She jokes just as Cassandra flips the file open, seeing an article about their unsub, named by the media 'The Seattle Strangler.' Four victims in four months; he keeps them alive for a week, no physical evidence, and he's just taken another woman.

The irony of her first case taking her to Seattle, of all places, is not lost on her.

"Word of warning, start packing a go bag." Morgan suggests as they leave to meet Reid and Gideon. "We get a lot of cases without warning, and it's easier to just have a bag packed at your desk. Sometimes we stay for days at a time. . . and you have a bag."

Cassandra laughs as she transfers her duffel bag from her car to the SUV they're taking, winking at Morgan as she passes him.

"I was warned that this job was go, go, go." She tells him. "I didn't expect it to be instant, but I figured I'd rather be over-prepared."

"Smart." Morgan holds open the back door for her, slipping into the passenger seat. Hotchner is driving. They go over the case in more detail on the way, with Hotchner asking her questions to test her. She makes notes of everything they point out in her case file, scribbling away in the back seat and feeling like a little kid working on homework.

Hotchner leads the way to Gideon's office, where he can be heard talking to Reid even from outside the room.

"I'll look the case file over. I'll get some thoughts to you ASAP."

"You're gonna be with us in Seattle ASAP." Hotchner corrects, walking straight into the office. Cassandra follows behind Morgan, feeling uncomfortable. She hates inviting herself into someone else's space, but she wasn't going to wait out in the hallway like a child either.

Gideon walks to them, taking his glasses off, while Morgan holds out a picture of the latest victim.

"23-year-old Heather Woodland. Before she left for lunch, she downloaded an email with a time-delayed virus attached. The killer's virus wiped her hard drive and left this on the screen." Hotchner hands over a picture of the computer screen.

For heavens sake catch me before I kill more I cannot control myself For heavens sake catch me before I kill more I cannot control myself For heavens sake catch me before I kill more I cannot control myself

No punctuation. 'For' is the only word capitalized: aside from the letter I, of course.

Gideon says the sentence out loud, walking over to a framed picture on his wall, showing that same sentence written above a bed in lipstick. Under the picture reads William Heirens, The Lipstick Killer, 1945.

Cassandra is pleased to have made that connection back in the car.

"He never keeps them for longer than 7 days, which means we have fewer than 36 hours to find her." Hotchner tells Gideon.

"They want you back in the saddle. You ready?" Morgan asks, sounding uncertain.

"Looks like medical leave's over, boss." Reid states.

Instead of answering them, Gideon's gaze hones in on Cassandra, who instinctively straightens her back. She's standing next to Reid, behind Morgan and Hotchner, but she might as well be directly in front of him for how piercing his stare is.

"Cassandra–" She starts introducing herself, sure that he couldn't possibly remember her after so many years, and a small smile appears on his face as he interrupts her.

"Cassandra Grey, studied criminal justice at Harvard. Yes, I remember. I was disappointed when your professors said you weren't pursuing the field after graduation."

Giddiness courses through Cassandra, although she does her best to keep her face impassive, not wanting to come on too strong. Jason Gideon remembers her. He kept tabs on her! Honestly, she would've switched fields years ago if she'd been told that.

"I went the medical path until I got a position on New York's SVU team." She explains.

"Did you work under Olivia Benson, or with a different unit?" He asks her, looking intrigued.

Cassandra can't help her smile at the mention of her previous boss, a woman who she adores. No one is more dedicated to the field than Olivia. Cassandra learned so much from her, and she wouldn't change a thing about her introduction to the police force.

"I was on Captain Benson's team, yes. Have you worked with her?"

"A time or two, yes. She's excellent at her job so there haven't been many opportunities, although she occasionally sends a case through for us to look through." Hotchner joins the conversation, turning to Gideon immediately after. "You can interrogate her more later. 36 hours, remember?"

"They sure they want me?" Gideon asks.

"The order came from the director."

"Well, we'd better get started."

They go over the case more on the jet. Reid sits next to Hotchner, with Morgan right behind him. Cassandra curls up on the couch behind him, hiding her hands in her pockets and jumping in when she has something to add. She doesn't look at Gideon when he passes her to join the men, not wanting to see him profile her.

It took her a year to be able to get on a plane again, and she still doesn't handle being in the air very well.

"His first victim was 26-year-old Melissa Kirsh." Reid states, looking through the case file. "Stab wounds, strangulation."

"Wait, wait. Back up. Back up." Morgan interrupts, frowning. "He stabbed her . . . and then strangled her to finish her off?"

"Other way around." Gideon corrects. "Why do you think he started using the belt with the second murder?"

"Strangulation with your bare hands is not as easy as one would believe." Reid answers, while Cassandra looks at the crime scene photos with a frown, gently tracing the strangulation marks with her finger. What an awful way to die. "He tried, probably found that it took too long . . ."

"So he stabbed her instead." Morgan continues.

"And realized it would be hours cleaning up the blood." Hotchner adds.

"Next time, our boy's got a method–the belt." Morgan finishes.

"He's learning. Perfecting his scenario." Gideon tells them, turning to look at Cassandra.

"Becoming a better killer."

Morgan holds the door open for them at the FBI Northwest Field Office in Seattle. Cassandra thanks him quickly, looking around as they enter the building. They have to go through a metal detector first, handing over their guns–Reid is the only one of them not carrying–and briefcases before they're allowed further into the building.

Gideon leads the way, while Morgan watches him with narrowed eyes.

"He never stands with his back to a window." Morgan murmurs to Reid while Cassandra clips her ID badge to her blazer. "When I was between him and a doorway, he asked me to move."

"That's hyper vigilance. It's not uncommon in Post Traumatic Stress Disorder." Reid tells him, stopping to talk to Morgan and giving Hotchner time to catch up to them. Cassandra doesn't say anything, knowing it's not her place as a new member of the team, but the conversation grates at her. She would hate it if anyone talked about her trauma like that–a fact she knows from first-hand experience.

"Just how much disorder are we talking about?" Morgan scoffs.

"Morgan, it's been six months. Everything's okay." Hotchner assures him, and while he looks hesitant, Morgan doesn't protest further. The office they're led to is crowded with bustling agents.

"This is Special Agent Gideon." Hotchner introduces them to the room. "Special Agent Morgan, our expert on obsessional crimes; Special Agent Reid—"

"Doctor Reid." Gideon interjects.

"Doctor Reid, our expert on, well, everything." Hotchner accepts the correction with a wry smile. "Special Agent Grey, our expert on sexual crimes. And after two years busting my butt in this office, I hope you remember me."

A lot of the agents laugh at the joke, and Cassandra gives a small smile, even as the joke intrigues her. He'd worked in Seattle?

"He's willing to travel with the body." Gideon notes from his position at a map.

"Then he drives a vehicle capable of concealing one."

"1 in 7.4 drivers in Seattle owns an SUV." Reid tells them, and Cassandra smiles.

"I was one of them." She admits, nodding her head. "We're a very car-dependent city."

"Explorer with tinted windows." Morgan throws out as an option for the unsub.

"Explorers rate higher with women."

"That's assuming it's his car." Cassandra points out just as Morgan asks 'How do we know it's his car?' They share an amused look before Cassandra continues. "The average car ownership here is one per household, and that is declining steadily since the city is putting more money into public transit. The car could be owned by a partner, mother, friend. We shouldn't rule anything out this early."

"Ted Bundy drove a VW Bug." Morgan points out, adding to her point.

"What about a Jeep Cherokee?" Hotchner asks.

"Jeep's are more masculine."

"We all know how an unsub feels about asserting his masculinity." Gideon states, turning away from the board.

"When did the bureau become involved in this case?" Hotchner asks the room.

"After the fourth body." One of the agents answers. He'd shaken all of their hands—excluding Reid, who'd politely declined the physical touch—but hadn't introduced himself in return. "He dumped that one out of state."

"On purpose."

"If so, knowledge of law enforcement does suggest a criminal record." Reid suggests.

"Or that he watches television. May I?" Morgan asks, quickly getting the agent's file handed off to him.

"Do you want to see our suspect list?"

"No, we won't look at a suspect list until after we come up with a profile. It keeps our perspective unbiased." Hotchner explains while Cassandra leans in to look at the file. Morgan moves it to make access clearer for her.

"When do we sit down with your task force?" Gideon asks.

"4 o'clock."

"An accurate profile by 4 o'clock today?" Morgan questions incredulously.

"That's not a problem." Gideon decides, walking back to the victim board. Cassandra sends Morgan a surprised look, getting one in return. She certainly didn't expect to have a deadline so short.

"Agent Gideon, where would you like to start?"

"Let's start at the site of the last murder." He decides, pointing to the crime scene photo.

"Morgan . . . go with him." Hotchner decides, turning to Reid. "Reid, stay here, analyze the geographical locations between the murder sights. Grey, you help him: you lived here and might be able to provide some insight."

Not exactly how Cassandra expected to spend her first day on the job, but she's not complaining.

Elle Greenaway proves to be a helpful addition to the case, luring the unsub out of the house to be arrested. They don't find Heather in his house, where he lived with his grandmother after his mother died in a house fire when he was 13.

Cassandra is willing to bet her entire savings account that he set that fire.

Gideon questions Elle on the sexual aspects of the crime, nodding in approval when she gives the same answers that Cassandra gave when they were going over the case on the jet. She stops Cassandra before she can move up the stairs, leaving the two of them alone for the first time since her arrival.

"Elle Greenaway." She introduces, holding out her hand. She has a firm grip.

"Cassandra Grey." Cassandra returns, smiling at her before she moves to follow her team up the stairs, unsurprised when Elle follows her and continues talking.

"Look, I have to ask–how did you get your spot on the team?" She asks, rushing to explain the question. "I've been trying to get the other available spot for years, so I just wondered if–"

"Look, Greenaway, just follow your instincts." Cassandra answers. "I worked in SVU before this, and I focused on helping every victim I could in any way I could. That apparently put me on the FBI's radar without me knowing. Just trust your instincts and it'll pay off."

"Instincts." Elle breathes out, nodding her head. "Right. I can do that."

Cassandra's advice pays off, with Elle proving herself capable as a major help in catching the second unsub. She joins the team, which is honestly a huge relief for Cassandra, who's no longer the only new person in the unit. It's a bit strange to listen to her be introduced as a specialist in sex offender cases out of Seattle: like looking into a mirror and seeing who she could've been, if she hadn't picked medicine.

Cassandra meets Penelope Garcia, their technical analyst, on their first day back from Seattle. She's standing by the coffee machine in the break room, impatiently waiting for a new pot to brew, her foot tapping away. She's wearing the most colorful outfit that Cassandra has ever seen in this field, with chunky rings and black glasses.

"I like your mug." Cassandra offers, leaning against the doorframe so as not to crowd the woman, eyeing her orange octopus mug with interest. She jumps slightly at her words, thankfully not bumping into or breaking anything in the process. "Oh! Sorry, I didn't mean to scare you."

"It's okay." She turns and beams at Cassandra, who smiles back, surprised at how bubbly she is. "I'm not used to most people being here this early. I'm Penelope, but most people here call me Garcia."

"Cassandra Grey." She introduces herself for possibly the thousandth time since she got to Virginia. She misses when everyone just knew her without her having to introduce herself in any way, but if repeated ice warmers are the cost of peace, she'll happily pay it. "I'm new to the BAU."

"Oh! I did hear that we got two new agents." Garcia realizes, reaching out to shake her hand. "I'm the team's technical analyst. I really only leave my bat cave for coffee, so it's good that you caught me now."

The joke loosens Cassandra up a bit, and she starts up a conversation around the woman's mug, getting a bright smile and a promise to be brought to the aforementioned bat cave later. Apparently Garcia is an avid collector of nicknacks. Cassandra is excited to see them.

By the time both of their drinks are made and they're saying goodbye, Cassandra has the terrifying realization that she would kill someone for Penelope Garcia.

Their next case takes them to Arizona. They gather around in the conference room while JJ and Hotch–a nickname that Cassandra became privy to at the end of their Seattle case–present the case to them.

"This is from the Phoenix office. Bradshaw College in Tempe, 6 fires in 7 months."

"Who recorded it?" Gideon questions.

"A student with a digital camcorder." JJ answers, while Cassandra flips through the case file, information jumping out at her. "He was watching a fire in the building across from their dorm. The other person you'll see is his roommate, 20-year-old Matthew Rowland."

She clicks play on the video, and they all watch as two boys talk about the fire, excitement heavy in their voices. Someone tries to enter the room–"is someone in the hallway?"–and then, just as Matthew states that it smells like gas, he's lit on fire. Nothing that his roommate does is enough to save his friend.

They're on the jet soon after, flying to Tempe in hopes of stopping the arsonist before more lives can be taken.

"There are two common stressors for a serial arsonist." Reid tells them, playing chess by himself.

"Loss of job, loss of love." Elle lists the reasons.

"When was the first fire set?" Morgan asks, typing on his laptop.

"March." Cassandra answers, having read that recently. She's currently on her phone, playing a round of tetris: she'd read a study that it helps distract the mind when doing something that causes fear. For her, that'll always be flying. The game at least distracts her a little bit, even as she listens and chips in to the discussions happening.

"The next one was in May, and the third one wasn't until September." Hotch continues. "Then two weeks later there were three in one night."

"He's speeding up. Fire's are closer together." Gideon points out. Cassandra just frowns, wondering what their unsubs stressor was, if the fires are so spread out until they suddenly clump together. Three in one night is a huge change from one every few months.

"Hey, Reid, you got a statistic on arsonists?" Morgan asks, inputting the data into his computer.

"82% are white males between 17 and 27. Female arsonists are far less likely, their motive typically being revenge."

"Sound's like our boy's a student." Morgan muses.

"Don't be so sure. You rely too much on precedent, you never allow for the unexpected." Gideon insists. "If he went from setting one fire to three in two week's time–"

"Rapid escalation." Hotch finishes the thought.

"He's gone from the power to damage a building to something far more satisfying. The power over life and death." Gideon continues his explanation. "Who are we talking to first?"

Cassandra can't help the way her hand lands on her left side, right over the burn scars hidden under her clothes. She can't imagine how much pain the victims of arsonists are in: her injuries hurt enough, and they were much more minor in comparison.

"Dean of students, Ellen Turner."

"No badges." Gideon orders as they're getting out of the car. "I don't want to satisfy the unsub's need for attention by letting him know he got the FBI here."

Cassandra barely resists making a face behind his back. She's pretty sure that's the kind of thing that should be thought of before they arrive on scene, not as they're exiting the black SUV's that just scream police. I mean, come on, the tinted windows are a dead giveaway. Also, why is he talking about them being FBI out in the open, if he doesn't want that to be known?

"Try not to look official." He says, and then turns to face them as he walks down the stairs of the college. "Try to look less official."

Morgan turns to face them, the same annoyance that Cassandra is feeling written all over her face. She shrugs back, stripping out of her blazer and unbuttoning the top two buttons of her shirt: not enough to be inappropriate, but enough to be more casual.

"I'd loosen those ties, boys." She grins, watching in amusement as Morgan does just that. Reid just stares at her, looking confused until Cassandra does it for him, being gentle and careful not to touch him in the process. "Perfect. That's as good as we're gonna get, I think."

They quickly meet up with Gideon, who is walking with Dean Turner and Hotch.

"Obviously, I'd rather be meeting you under different circumstances." She sighs, looking exhausted yet put together in a tasteful floral green dress. "This is Fire Instructor Zhang."

"This morning, the chemistry department reported several bottles of highly flammable chemicals missing." Zhang reports.

"I'm prepared to evacuate this campus." Turner tells them seriously, while Hotch and Gideon each grab one of the doors, opening them for her. "Thank you."

"That brings with it its own problems." Hotch explains to her.

"You might evacuate the arsonist as well."

"I know that might sound like a good thing, but the fires would only start up again when campus reopens." Cassandra tells her, seeing the confusion on her face. "The arsonist might see it as a challenge."

"Wait, Hotch, Gideon, hold on a second." Morgan interrupts, and they all stop and turn to him. "You said the chemicals were missing today."

"Uh-huh."

"It says here that one of the previous fires was set with diesel fuel that disappeared from the grounds keeping facility." He points out. "How long after it disappeared was the fire set?"

"One day." Turner tells them grimly.

They all share a look, knowing what that timeline means for the kids on campus.

Reid makes an important realization: the fire was set from outside the dorm room, meaning that their unsub wasn't able to stop and watch, needing to escape quickly. That doesn't fit the profile of a serial arsonist, since they enjoy experiencing the fire.

Why would he set a fire he couldn't watch?

The question grates on Cassandra as they gather around Zhang, who is explaining the fire patterns to them. Something about this case feels wrong in a way she can't put her finger on.

"They turned the water off just before the fire." Zhang explains, opening a box containing the device. "The last three were set with these. Two devices, simultaneous ignition."

"There was no device used on Matthew Rowland." Gideon points out. "Unsub set that one manually."

"He wanted to be there." Morgan answers Gideon's unspoken question. "To enjoy the kid's death."

"Not necessarily." Hotch objects.

"Well, if the target was Matthew Rowland, then why set the other two fires?" Elle asks.

"Motives for arson are relatively simple. There's vandalism, crime concealment, political statement, profit—"

"And revenge." Hotch finishes for Reid, who nods.

"We're assuming that Matthew was a target." Cassandra points out. "He could've just been a victim of opportunity."

"We interviewed Matthew Rowland's roommate." Zhang tells them. "He said that Matthew was very well liked. No reason for revenge."

"What about vandalism?" Turner questions.

"No, the fire's are too sophisticated." Elle shakes her head. "If he's trying to make a political statement, he's not being too clear about it."

"There's an underlying strategy in this case." Gideon says. "Matthew, firefighters, injured victims. To the unsub, they're not people, they're . . ."

"Objects." Hotch fills in the sentence, frowning.

"More like, uh . . ." Gideon hunts around for a different word, and Reid perks up.

"Chess pieces."

"Exactly." Gideon breathes out.

She gets sent off with Morgan to try and get in the unsubs head, and the two of them walk out into the hallway. She looks around, taking in how many doors are in this section of the campus alone. If she was an arsonist, this place would be crawling with opportunity.

"Alright." Morgan speaks up, drumming his fingers along the handrail as he walks. "I want to set a dormitory on fire. Where would I start?"

"Heat rises." Cassandra points out, leaning against the railing next to him and looking up. There's plants covering the upper levels. "If I was setting a building on fire, I'd start at the bottom. Fires can be extinguished with air, but a basement would take care of that issue."

"And the upper levels would be fuel." Morgan adds, agreeing with her. "So why start on the third floor?"

Cassandra is fairly certain that the both of them are remembering the way Matthew had screamed for help as he died, all captured on his roommate's phone.

"It was personal." Cassandra notes, frowning. "He tried entering the room first, and then set the fire when he couldn't get in."

Why try to enter at all?

"It wasn't the building he wanted to set on fire." Morgan sighs, sharing a disturbed look with her. It's frightening to know that this is about more than an obsession with fire. Does he have a list? A known group of students to target?

How long until he kills again?

As if he heard her thoughts, the fire alarm in the building next to them goes off, the shrieking noise filling the air. She takes off with Morgan, the two of them sprinting down the stairs until they reach the building, where students are rushing to evacuate as smoke seeps out of the entrances.

"Hey, you're okay." Cassandra helps up a young girl who gets shoved down, watching as she rushes away without so much as a look back as soon as she's on her feet. She really can't blame her for wanting to get away from the scene.

Her and Morgan have to be the only one's insane enough to run toward a fire.

Except . . . is the unsub still here? He has to be. What's the fun of setting a fire, if you don't stick around to watch everyone panic afterwards?

She has her phone out before she can question it, spinning around as she records everything around her, zooming in on as many people as she can. She catches a glimpse of Hotch sprinting toward them, and of Morgan pulling Gideon out of the building, the agent fighting him every step of the way. Every student she captures through her lens looks terrified: she sees no interest, no glee, no exhilaration. Nothing to tie back to their unsub.

The team gathers at the bottom of the staircase, but Cassandra takes a detour when she sees the way Gideon and Morgan are coughing. One quick conversation with one of the firefighters pulling up to the scene later, she's passing them two water bottles and patting Morgan on the back, worried about what they've breathed in.

"Take pictures–as many as you can." Hotch quietly orders Elle, who is quick to do just that.

"I took a video." Cassandra offers. "We can compare it with the pictures."

Hotch nods, giving her a pleased look, and she tries not to look too happy as she turns back to Morgan, forcing him to drink more water.

"Trust me on this. Smoke inhalation is no joke." She insists, watching until he drinks the entire bottle and making a mental note to monitor his and Gideon's intake throughout the case. Drinking water can be the difference between a sore throat and a hospital visit, and she has no intentions of letting either of them worsen their health.

They take a minute to process before they separate. Morgan goes to find the police and Cassandra goes to find campus security, both of them explaining the need for interviews from everyone in that building. A lot of the students are far gone by now, but with class schedules they can figure out who was in the building at the time.

Afterward, they meet back up in the security office, reviewing the pictures that Elle took and had printed, along with Cassandra's video. It doesn't matter how many times she watches it, she finds absolutely nothing helpful in it or in the pictures. It's just a bunch of shocked and scared students.

"We've been at this all night, and we've got nothin'." Morgan gripes, throwing down a photo of a girl being comforted by a guy. Hotch has his eyes shut, his fingers pressed together at his forehead. "Look at these expressions. We got fear, a touch of horror, even a little bit of panic. Where's the guy gettin' off?"

"When asked about his motives, Peter Dinsdale said, 'I am devoted to fire. Fire is my master.'" Reid quotes.

Morgan scoffs, pacing around the room. "Okay, so who was our boy's master? 10,000 plus students. . ."

He lights his lighter above his head, turning to face them again.

"And one has a serious fascination with fire."

"Arsonists always have a background." Cassandra states, even though they all already know that. Sometimes, with cases, it's better to state the obvious: they spend so much time looking for the abstract answer that they miss what is right in front of their face. "He'll have a history of pyromania . . . if he's rooming here, then surely a roommate has noticed something."

"That's if he has a roommate." Morgan points out, and Cassandra sighs, conceding the point. This case is feeling more and more helpless as they go.

"Fire starting is one third of the homicidal triad." Elle reminds them, scribbling down notes on a white board. "An early predictor of adult dissociative criminal behavior. If we looked in his childhood, we'd probably find all three: bedwetting, and cruelty to animals."

"Absent or abusive father, trouble with the opposite sex, chronic low self-esteem–M.O. would be dynamic." Gideon adds. "Evolvings, fire setting escalates, they thrive on panic, fear. It's just the standard profile of a serial arsonist."

"Based on hundreds of interviews."

"Based on precedent." Morgan follows Reid's statement, spinning his lighter around. He rolls his eyes when Cassandra tosses him another water bottle, but he doesn't protest as he uncaps it and starts drinking.

"Everything the unsub should be, according to research." Elle sighs, frowning at her board of thoughts.

"Everything he's not." Cassandra sighs, leaning back in her chair and rubbing her eyes. She's spent too many hours analyzing every frame of her video, and her head is starting to hurt.

"We're off the mark." Hotch agrees, sliding a bottle of ibuprofen to her without her having to ask for it. Profilers. She thanks him but he brushes it off with nothing more than a nod.

"Because of the two missing elements." Gideon continues, with Morgan immediately bouncing off of his thought.

"Sex and power–the two motives that drive a serial arsonist."

"And without 'em, we do not have a profile." Gideon sighs.

Hotch, Reid and Cassandra end up in a chemistry lab, since a chemistry student had told Dean Turner that they knew how the unsub was setting the fires. Hotch asks Reid to do the speaking, since he's closer to their age, and Cassandra watches as he forces himself to speak up, clearing his throat first.

"Hi–hi, guys. Uh, my name's, uh, Dr. Spencer Reid. I'm a, uh, agent with the–the BAU, the Behavioral Anaylsis Unit of the FBI, which, um, it used to be called the BSU, the Behavioral Science Unit, but not anymore. They changed it to the BAU. Um, it's part of the NCAVC, the National Center for the Analysis of Violent Crime, which is also part of this thing called the CIRG, the Critical Incident Response Group–"

"What he's trying to say is we'd love to know how you can help us." Hotch interrupts just as Reid walks around to join them. Reid looks relieved to have the pressure off of him, and Cassandra notices the way the students go from sharing amused looks to serious at the reminder of why they're there.

"May I, please?" One of the students asks, standing up and grabbing the lightbulb that Reid is holding. He gives him a smile when he hands it over. "Thank you. See this?" He holds it up for them. "Drill a hole in the side, fill it with gasoline or whatever's good and flammable, turn the light on, boom. That's what went down, didn't it?"

"This stuff's all over the net." A woman adds. She's sitting in the back of the lab. "Wanna know how to make a Molotov Cocktail that sets itself on fire? Potassium, sulfur, and normal sugar . . . sugar . . . sugar, which is–"

"Not exactly plutonium." The other student adds, looking amused. "You could get this stuff anywhere."

"Sugar from the supermarket."

"But you don't need to be a chem major to know that." Hotch tells them.

"Do you think it's a chem student?" Zhang asks, looking at the girl who spoke.

"You wanna know what I think?" The guy asks them, bringing the attention back to them. "I think–" He holds the lightbulb to the top of his head, mimicking having a lightbulb moment. "It would be a good time to take the semester off."

He taps the lightbulb to Reid's chest, handing it back to him.

As soon as Hotch has pressed the button to bring them back to their makeshift office, that same student reaches out and inserts a key into the elevator.

"Hold on. You need a key to get moving after 10 pm." He explains to them, smirking at Hotch.

"So what are you still doing here?"

"I can't leave. We've all got projects. You know how to solve the 3 body problem? Computing the mutual gravitational interaction between the earth, sun and moon?" He asks, and while Reid nods his head next to her, Cassandra's first thought is Lexie will be so interested in this.

Reality slams in a second later, as it always does. The last three years has taught her how to stay standing when these thoughts happen, and they happen often.

They get a recording from a call sent to the office next to Wallace's, the now deceased professor, from five minutes before the fire was set. It's muffled, and hard to make out one of the words, sounding almost like Karen.

Karen. I do this for Karen.

Except that the second time it's played, it sounds like more of an 'oh' sound, like Care-own. Cassandra points that out, even though it's more likely that the unsub is saying Karen.

"What is it?" Hotch asks after Gideon has Morgan replay it multiple times.

"I'm not sure. Somethin' about it." Gideon whispers, his eyes squeezed shut.

"Is this tape clean?"

"I can put it through some audio filters." Garcia tells them from Morgan's computer, on a video call with him.

"Look, we need as close to the real voice as you can get, and anything that might be in the background." Morgan explains. "Can you do it?"

"Okay, you know how on Star Trek when Captain Kirk asks McCoy to do something totally impossible, and McCoy says, 'Damn it, Jim, I'm a doctor, not a miracle worker.'"

"Hey, what are you tellin' me, not to expect a miracle?"

"No, I'm saying I'm not a doctor."

"That's a good line. It's a shame we can't use it." Cassandra whispers to Reid, who gives her a smile.

"That's my girl." Morgan laughs, beaming at Garcia before hanging up.

They get a list of all the Karen's on campus, complete with pictures, and split the stack between Elle, Morgan and Cassandra. They get them all to come to them, lining up in the hallway as they conduct individual interviews.

"You know, there's gotta be a faster way to do this." Morgan groans as Elle closes the door after Karen number 7. "How 'bout we just change the first question to 'Have you recently dated a homicidal pyromaniac?'"

Elle and Cassandra both laugh, sharing amused looks as Elle sits down in the Karen seat. She's been taking notes while Cassandra and Morgan alternate asking the questions.

"Speaking of questions. You figured out yet why the Footpath Killer stuttered?" She asks, referring to one of Gideon's past cases.

"Nope. You?" Morgan asks her.

"I know that embarrassment makes a stutter worse, and that when you're flustered, it's more difficult to control the articulatory musculature of the face." Elle explains, and Cassandra hides her amused smile into her mug.

"You sound like Reid." Morgan points a finger at her.

"You did not just say that!" Elle laughs, shaking her head.

"Obviously, somebody's been doing their homework." Morgan teases while Elle gets up to let in the next Karen, turning when Cassandra chips in.

"Hey, Elle?"

"Yeah."

"You're thinking about it too clinically." She advises, and Elle frowns in confusion as she brings in Karen Number 8. It's true though: she's focused too much on something that no one can fully prove. The Footpath Killer stuttered because he stuttered. Any explanation Gideon gave him wouldn't be correct, not really. Cassandra imagines he was just buying time by offering up an explanation for something he was ashamed of.

"Hey, Grey!" Morgan calls out, having just gotten off the phone with Garcia. "You were right about it not being Karen. It's actually something more like–"

"Charown." Gideon bursts into the office, facing Reid.

"Charown?" He repeats, frowning.

"Charown. I do it because of Charown." Gideon tells them, although it's clear that he's mainly focused on Reid, waiting for an epiphany.

"That's Hebrew." Reid tells him, which is more than Cassandra and Morgan knew, sharing confused looks with each other.

"It's God's burning anger."

"Yeah."

"Wait." Cassandra stands up, intrigued. "That makes the motive religious."

"Well, you know, in a lot of religions God is related to fire." Reid tells her, all of them gathering together to watch Gideon wipe the white board clean.

"Well, Brahman is fire in Hinduism, and the Jews see God as a pillar of fire, and Christian's worship God as a consuming fire." Hotch explains. Cassandra hums, not having known that about Hinduism, and making a mental note to research that later. As someone nonreligious, religion is intriguing to her.

"Okay, so we're looking for a theology major." Morgan suggests, but Cassandra shakes her head.

"Some of the most religious people I know never studied it." She points out, thinking of the students she knew back in college.

"Maybe he's punishing the other students for their sins." Morgan continues explaining his thought process, and Cassandra tilts her head. There could be something to that.

"What–what's the most sinful place on campus?"

"Come on, Elle. When I was in college, that was everywhere." Morgan scoffs.

"Fraternity?" Hotch suggests.

"I mean, I got up to some sinful things at Queen's Head–that was my campus bar." Cassandra reminisces. Those had been some fun days. Morgan looks proud of her, and she laughs as she fist bumps him.

"That's not consistent with the previous targets." Hotch points out, bringing them back to earth.

"What about the idea of baptism by fire?" Morgan offers. "Aren't we all supposed to be tested through fire in Revelations?"

"Hotch, you might be onto something with the fraternity angle." Cassandra admits, remembering the video of the fire that killed Matthew. "In the video, Matthew said 'there's always fires during Rush Week.' If he views fraternities as a sin, it could explain setting the fire . . . although neither of the boys targeted were in a frat. So maybe not."

"Look, it's good, it's good." Gideon speaks up, finally turning away from the white board, where he's been scribbling down everything they've suggested. "But let's please do not jump to conclusions. Religion might be a part of it, but it's not necessarily the prime compulsion."

Isn't our whole job jumping to conclusions?

"Gideon! Rush to conclusions, jump to conclusions. Who cares?" Morgan bursts out. 

"We're running out of time!"

"Compulsion." Reid blurts out.

"Okay, we need to get a list of students in theology classes." Cassandra sighs, even though she isn't sure that they'll necessarily be in those classes. "And any clubs or anything related to religion that happens on campus."

They all split up, with Reid remaining behind, reviewing the footage again.

Morgan puts his phone on speaker, and they listen as they're given the apartment information of their unsub, who isn't a male but a woman with scrupulosity: a form of OCD that's religion based. Reid is the one to piece it together after watching her turn the doorknob three times before setting the fire to kill Matthew, who was in a class taught by the deceased professor—his third class of the day. Any convergence of three's causes the unsub to act, which is why Professor Wallace was targeted: his office was in room 3 and he taught at 3 pm on Tuesdays, the third day of the week. The first fire occurred on March 3rd at 3 pm: the third hour of the third day of the third month.

"Holy shit." Cassandra breathes out, sharing a surprised look with Derek before her eyes widen. "Hotch, is it the girl from the chem—"

"Yes." Hotch interrupts her, and she shuts her eyes, remembering the girl with the stutter. Sugar . . . Sugar . . . Sugar. The answer was right in front of them this whole time. "Her name's Clara Hayes. Did you get the address?"

"Yes." Derek answers, hanging up as they rush down the stairs. "Her apartment's off campus."

"But how is he sure it's this girl?" Elle asks, following right behind them along with two police officers.

"She listed the ingredients for a light bulb bomb for us." Cassandra explains, remembering the way she'd twisted her ring around her finger—a normal action that Cassandra had brushed off, but now recognizes as a compulsive need to twist it three times. "Potassium, sulfur, and normal sugar, sugar, sugar."

"Okay, so she repeated a word three times." Elle says, sceptical. "That's circumstantial at best."

"No, she was doing everything in three's. Twisting her ring, counting on her fingers, repeating a word three times. All in three's. And one of her classmates said that they were working on a solution to the 3 body problem."

They arrive at Clara's apartment quickly, with the police being the first ones through the doorway. It's quickly apparent that the apartment is clear, and the five of them stare around the place in shock. Every square inch of the walls are covered in pictures, newspaper articles, and quotes from scriptures about fire.

"Oh, you gotta be kidding me." Morgan chuckles, looking around while Cassandra stares at the stuffed animals on the bed, not fitting in with the darkness of the room. "OCD? I'm thinking more like OMG."

Cassandra laughs at the comment, her eyes darting around the room in search for a needle in a haystack: any information about her next plan to set a fire, while surrounded by quotes about fire.

"OMG?" Elle asks, and Cassandra side-eyes her, wondering which hole she lived in to not know that.

"Oh my god." Morgan tells her.

"'A fire is kindled in my anger, and shall burn in the lowest hell.' Deuteronomy." Elle reads one of the quotes, raising her eyebrows as she puts away her gun.

"'And again the fire of heaven came down and killed them all.'" Morgan reads, while Cassandra spins around, trying to take in the entire room. It's overwhelming. She has the word PERISH written nine times on one paper, next to a picture of a blaze.

"'I do this for Charon.'" Elle reads, and Cassandra turns to see her looking at a picture of the Greek Mythology figure. "That's Charon. That's the Greek Mythological ferryman of the dead."

"It's also the name of Pluto's only moon." Morgan adds.

"Charon is described as having eyes of fire in the poem Inferno by Dante Alighieri, from Divine Comedy." Cassandra tells them, remembering her experience reading the set of poems. "Dante was actually exiled from Florence. If he had returned, he would've been burned at the stake."

"'Paradise lost.'" Morgan reads out, observing the wall to their left. "'Moloch, horrid king, bedmates with blood of human sacrifice and parents' tears.'"

"Moloch sounds familiar." Cassandra frowns. "I don't remember why . . ."

"Well, that's easy." Morgan snorts, pulling out his phone. He reads the passage again, putting the phone on speaker.

"Moloch was the demon sun god of the Canaanites." Reid explains instantly, and Morgan winks at her, looking pleased with himself. "In order to keep from incurring his wrath, the people would sacrifice their children to him by burning them alive."

"Oh, pleasant." Cassandra says dryly, wrinkling her nose. "Thank god for modern society, I guess."

"16-year-old survives inferno." Hotch reads from a newspaper, talking about Clara's past. "The mother Ellen Hayes called it a miracle. 'My daughter was tested by God. He tested my child and she came through blessed.' Look at the house number."

"If it doesn't involve three's, I'll eat my own foot." Cassandra bets, shaking her head as she continues reading through the verses.

"333." Gideon answers.

"Hey, Morgan, Grey?" Elle asks them, and they grunt, still searching through the room. "You know what magical thinking is?"

"Obsessive thoughts." Morgan answers, raising an eyebrow. "It's like a superstition. It controls them."

"Kinda like 'step on a crack, break your mother's back.'"

"Except she actually believes it."

"Her trauma around her own fire manifested into believing it was her destiny." Cassandra marvels, considering that. It's hard to wrap her head around nearly dying in a fire, only to go on to set them for others, but she knows there's nothing logical about OCD or trauma.

Who is she to judge, anyway?

"God tested her with fire, and now when three 3's show up around another person—"

"God tells her to test them." Morgan finishes, while Cassandra ghosts her fingers along a journal next to her bed. Unsurprisingly, it's full of verses and scripture, no hint of a plan for anyone else. Their job is never that easy.

"You guys need to find the next pattern of three's." Hotch tells them, and they share a frustrated look.

"Hey, Hotch. . . we're lookin', man." Morgan huffs. "I don't think she would've left behind a day planner that says 'set next fire here' written in it."

"I can confirm she didn't." Cassandra tells him, holding up her journal.

"Thank you. Hotch, I under—wait till you see this place." Morgan snaps, rolling his eyes at Cassandra in a look what we deal with way.

"Guys." Elle grabs their attention, having found shelves hidden behind hanging beads on one of the walls.

"I'll call you back." Morgan hangs up instantly, and they move across the room to join Elle.

There are shelves of homemade bombs and timers.

Morgan calls Hotch back while Cassandra rushes to evacuate the building. There's a fire alarm right down the hall and she pulls it, the alarm piercing the air as she starts banging on doors and rushing people out.

"FBI! You need to evacuate the building." She repeats over and over, helping usher people to the stairs, discouraging the use of the elevator. "Elevator's are shut off. Take the stairs and be careful! No shoving!"

She feels like an elementary school teacher instead of an FBI agent.

"They're evacuating campus." Morgan joins her outside, where she's just finished explaining everything to the fire Captain who showed up. The poor man is exhausted, but relieved that there hasn't been a fire here—yet, at least. "No sign of Clara, but they're looking in the science building now."

"Where's Elle?"

"Making sure the top floor is evacuated. She should be coming now." He assures her.

They leave the scene as soon as Elle is out, but by the time they make it to campus, Clara has already been taken care of. She'd locked three of her classmates inside of an elevator, dousing them in gasoline, but Hotch and Gideon had stopped her before she could set the fire.

They saved those three, and the rest of the campus. That's something to be proud of.

"There's a bar nearby, if you want to celebrate." Morgan offers once they're leaving the plane, and Cassandra hesitates. On one hand, she'd love to let loose and shake this day off of her, but . . .

She's just not there yet.

"Another time." She promises, hating herself a little bit when he concedes and she watches him go convince Elle and Reid, an arm wrapped around their shoulders. They laugh at him, joking about something that Cassandra isn't a part of, and she's conflicted between joining them after all or keeping her distance.

In the end, she finishes her night curled up on her couch with a glass of wine and a random Hallmark movie playing in the background. If her sister was here, they'd be creating drinking games: take a shot when a "big city" person moves to a small town, take a shot when they get snowed in. Those movies were always their secret pleasure; cliche, but dependable. Now, as much as Cassandra tries, she can't focus on them without feeling like her heart is being ripped out of its chest.

She has a hard time sleeping that night.

authors note

chapter 1 is done (and i fear it was boring)

i want to address a few things right out of the gate:

1. cassandra is not some super genius agent that will solve every case. that role is reserved for her man. seriously, though, she's not going to instantly have all the answers and steal everyone else's lines constantly. no offense to any writers out there but that's one of my pet peeves. of course, there WILL be cases that she figures out faster than the others... otherwise, why is she on the team? it just won't be constant, and she's not going to know as much as the veteran agents. she's only been in the field for two years, keep that in mind.

2. i'm not going to write every single episode, because i feel like that's unnecessary and will lead to me getting burnt out. honestly some of the episodes don't interest me, and some of them she wouldn't be a huge help with/wont do anything for the plot, so im not going to spend hours writing those.

if there are any episodes you really want to see, drop them here and i'll do my best!

3. this is SLOW BURN! if you're coming from my greys anatomy fic, then you understand that i mean it when i say that. don't expect them getting together quickly because i don't do that.i yearn for yearning.

4. grief is prevalent in this fic, if that's not already clear. unfortunately i love writing traumatized characters. cassandra has been grieving for three years now, although there's no timeline for that ofc, so she isn't a constant mess. however, grief—especially the kind of traumatic, life-changing loss that she's gone through—changes people, and she's no exception. she's not going to walk around and ignore everyone and make no friendships at all, BUT she also isn't jumping into bonds with people. which is why she turns down offers to hang out but is willing to be kind and make small talk with her coworkers.  i just want to say that straight away because i know a lot of people get mad when there aren't instant relationships developed, but i personally don't think it makes sense to have instant bonds with traumatized profilers tbh. but the foundations are being set as we speak ❤️

super long authors note but i just wanted to get all that out. i'm so grateful for all the love being sent this fic's way already, you're all so sweet. as always, id love to hear any thoughts you have as you read (please don't be a silent reader)
🤍🤍🤍