My name is Barry Allen, and I am the fastest man alive. When I was a child, I saw my mother killed by something impossible. My father went to prison for her murder. Then an accident made me the impossible. To the outside world, I'm an ordinary forensic scientist, but secretly I use my speed to fight crime and find others like me, and one day I'll find who killed my mother and get justice for my father. I am the Flash.

The Night of the Particle Accelerator

A person with long black hair, fair skin, a green left eye and a blue left eye was walking around in a haunted house. They had a flashlight in their hand to guide them till it turned off.

"What the? I just changed the batteries." The person grumbles.

A strange presence was felt by them till they got flung back into a wall as the Particle Accelerator at S.T.A.R labs blew up. The presence that was felt happened to be a ghost who got flung into the person. The person lays on the floor with their back against the wall as their skin turns transparent.

S.T. A. R Labs After the Particle Accelerator

Shortly after the Flash had stopped Hannibal Bates, the shapeshifting meta-human, Cisco and Joe had discovered the real body of one Harrison Wells from Starling City almost decomposed. Now they needed to figure out who the imposter Wells is and why he has been helping Barry become the Flash. It was another normal day for the Flash, catching thieves for the police, stopping car chases. Barry still had to keep Iris in the dark about him being the Flash which was eating him alive with guilt. Cisco and Caitlyn were trying to figure out a way to find out Wells' real identity but so far they kept coming to dead ends.

That is until one case that had the police baffled; a robbery at the Central City Jewelry store except nothing was stolen, but the guards were in shock and muttering something about the flickering lights and a woman screaming. Joe decided to call Barry about it thinking it could be a meta-human but before he could tell him about it there was a report of someone attacking civilians in a bar.

At a bar in the downtown of Central City, a person with transparent pale skin, long black hair and pure black eyes was scaring people. They turned invisible and started throwing glasses at people. The glass shattered onto the floor as some of the glass cut some of the bar goers. The person laughed, the laugh sounding really eerie. Flash appeared onto the scene searching for the meta. "Guys, I don't see the meta." Flash stated into the comms.

"Hang on, I'm getting a heat signature. Near the drinks!" Cisco pointed out.

Flash sped up his arms in a circular motion creating a wind blast that hit the meta as she turned visible and went crashing into the drinks getting soaked in beer and wine. The meta stood up to face the Flash with a wicked grin, "You shouldn't have messed with my haunt, Speedster." she said in a low voice.

The Flash's eyes widened recognizing the voice. "Mushroom..?" He said in disbelief.

"I'm sorry but Mushroom is asleep right now." She says.

She grabs a glass and throws it at someone. The Flash runs in front of the person and catches the glass. The meta now known as Mushroom runs out as he does this. The Flash sighs seeing how Mushroom isn't there.

"I lost the meta." He says into his earpiece.

"How did you lose them?" Caitlyn asks.

"I'll explain later." Flash stated.

As soon as he rushed back to the lab, Cisco, Caitlyn, Wells, and Joe were already waiting for him. Barry explained that the meta was someone's name is Mushroom. Joe immediately knew the name, that was Barry's little sister. "Mushroom? Really?" Cisco asked.

"Her name used to be Sabrina Allen but after a while she changed it to Mushroom, they're non-binary. They are really big into the supernatural and became a ghost hunter. But I haven't heard from them since." Barry explained.

"Mushroom used to live with us but they moved out a year ago and now they have their own apartment in Central City." Joe stated.

Caitlina searched up Mushroom's name on the recognition software and a picture of a 24 year old woman with long black hair, fair skin, a green left eye and a blue left eye appears on the monitor. Barry stated that the woman was indeed his sister; Cisco did ask about their eyes and Barry explained that they have Heterochromia, a condition in which each eye is a different color.

"But they didn't look like that when I saw them," Barry says.

"Then how did you know it was your sister?" Cisco asks.

"I grew up with them glued to my side. I know my sister when I see them"

"How did they look different?" Joe asks.

"They looked... ghost like."

"Ghost like?" Wells asks as Barry nods.

"How ghost like though?" Caitlyn asks.

"It was weird. Their skin was transparent and their eyes were..black. Pure black." Barry explains.

"Take a look at this." Cisco pointed to the monitor, "Mushroom was declared missing the night of the Particle Accelerator explosion. They were last seen heading into a haunted house on Tenth Ave."

"OK, Joe and I will check out this house, see if we can find any clues on what happened to her..."

"Before the Phantom Menace strikes again." Cisco finished.

"Really?" Caitlyn asked.

"What? We have to call their alter ego something"

Barry rolls his eyes and leaves S.T.A.R labs with Joe to go to the haunted house.

Haunted House on Tenth Ave

Barry and Joe looked at the house which looked old and abandoned. They both looked at each before walking in.

"I will never understand how Mushroom loves these places." Joe comments.

"You and me both" Barry agrees.

As they looked around they could tell this house hasn't been lived in for years. The floorboards squeaked as they walked, doors creaked when opened and there was an occasional rat in the wall. They soon made it to a bedroom with a mattress on the floor with fresh sheets.

"It looks like someone has been sleeping here." Barry says as he walks in the room.

Suddenly, the window shutters slam open and close, startling both Barry and Joe. "Just the wind." Joe convinced himself.

Then the ghost became visible with just her face in a scary look, "Get out of my house!" she shrieked.

"Mushroom stop please. It's me. It's Barry," he says, trying to calm her down. She becomes fully visible as she tilts her head.

"Mushroom isn't here!" She says and tries to punch him.

Barry dodges it and runs behind her, he grabs her from behind to stop her from attacking him. Joe stands there shocked as Mushroom holds her breath and goes through his arms to get out of his grip.

"What the...?" He trails off.

Mushroom lets out the breath as soon as Joe hits her in the back of the head with his gun, knocking Mushroom unconscious. Barry looks at Joe shocked, "Let's bring them back to S.T. A. R. labs." Barry stated.

Barry super speeds Joe and Mushroom back to the lab where Caitlin had already set up the med wing for Barry's sister. Barry laid them down onto the bed and hooked them up to the heart monitor and an IV line. Except the heart monitor was in a flat line instead of a heart beat spike. "That's weird. They don't have a heartbeat." Barry pointed out.

"I think I know why. There are traces of dark matter radiating off their body but it's not just their body anymore, it's the ghost's body as well." Caitlyn stated.

"So are they possessed by this ghost?" Joe asked.

"Not exactly. Just like how Ronnie and Professor Stein are linked, this ghost and Mushroom are linked as well. Except the only difference is that they both share the same body, in other words they are fused together. Think of it like Jekyll and Hyde. Mushroom would be Jekyll. And the ghost would be Hyde." Wells explained.

Mushroom groaned, catching everyone's attention. They opened their eyes showing they were ghostly white. They sat up and held the back of their head.

"What the...?" They muttered.

"Mushroom?" Barry grabbed their hand. They looked at him and their face lit up.

"Barry!" They yelled and hugged him tightly. He chuckles and hugs them back.

"It would seem Mushroom is in control." Wells said.

Mushroom let go and looked at everyone but Joe and Barry confused. They look at Barry, "Don't worry. They just want to help," he reassured, "Tell us what happened."

"It's a bit of a blur. One minute I was in the haunted house, looking for this ghost. The next I heard a sudden explosion and I was flung into a wall and then everything went black. I kept feeling like there was another person inside me, controlling me, and there was nothing I could do. What's happening to me?" Mushroom asked in a panic.

Barry slowly broke down the news to his sister about the accelerator explosion, the meta humans, and even how he is the Flash. He also told them about the ghost that had merged with their body that Cisco dubbed The Phantom Menace. "Phantom Menace? Seriously? A Star Wars reference? What's wrong with just calling her, Ghost? It's simple." Mushroom complained.

"Ghost? Are you serious?" Cisco asks.

"Yes!" Mushroom yelled, their eyes turning black for a split second. Barry grabbed their hand to calm him down. Cisco put his hands up in surrender

"It seems that Mx. Allen isn't as fully in control as they think" Wells comments.

"Just call me Mushroom" Mushroom says.

"I would like to run some tests on you. Is that ok?" Caitlyn asks.

"Yeah. Of course."

"Can I stay with them?" Barry asks.

"I think it's best if you stay outside." Caitlyn says.

"We'll leave you two to it then." Wells says as he wheels out of the room.

Barry kisses Mushroom's forehead before he leaves the room with Cisco and Joe. Caitlyn began running a few tests on Mushroom to see how they could remove this Ghost without hurting them. Unfortunately, all the tests she ran claimed that this ghost couldn't be removed without killing Mushroom. So the ghost and Mushroom are officially fused together permanently. "Are you sure you can't do anything?" they asked.

"I'm sorry. But no." Caitlyn said, in a sad tone.

Mushroom sighs and nods. Barry was watching from the other side of the door as the two talked.

"I never thought me and my brother would have powers." Mushroom chuckles.

"Your brother has done some pretty amazing things," Caitlyn smiles.

"Really?"

"Yeah. He saves people."

"Sounds like him," Mushroom chuckles. They look down at their transparent hands seeing how they can see her pants through her hands.

"You really are like a ghost," Caitlyn pointed out.

"It's crazy. I have always loved everything supernatural and now I'm a ghost meta. It's ironic." Mushroom stated with a smile.

"What can you tell me about that haunted house?" Caitlyn asked.

"There's not much information on it." Mushroom replied, "I only know that no one has bought the place in over thirty years and that anyone who stays the night in there, gets chased out by the ghost."

Mushroom suddenly felt the ghost trying to take control, her eyes were turning black. Caitlyn tried to calm her down but the ghost completely took over Mushroom and attacked Caitlyn. "Take me back!" she shrieked.

"Uh guys!" Caitlyn yelled, making Barry run into the room.

Mushroom turned invisible and seemed to disappear. Everyone went into a panic and tried to find them.

"We may need to lock them in the pipeline," Wells said. Everyone agreed even if some didn't want to.

They all heard footsteps but no one was walking. Barry immediately knew it was Mushroom and ran in the direction of the footsteps. Mushroom became visible in the hallway since it had been an hour. She huffed in frustration. "Get out of my way Flash."

"Mushroom, I know you can hear me. You have to fight it, sis. Don't let Ghost take control of you." Barry pleaded.

"Like with your powers?" Ghost asked, smugly, "Yeah, whatever my hosts sees and hears, I see and hear. You break the laws of physics and become a hero, but when I do it, I become the enemy. Now that's just not fair. I like being in control, I like power, and now all of Central City will know my name."

"It's different with me. I am using my powers for good, you're using yours to cause havoc"

"So? As long as they know my name. Besides, all I have known is causing havoc and scaring the living. And now that I am fused with this host, it's so much easier. Though they do fight and that's just annoying." Ghost was about to leave till Barry grabbed her arm.

"Don't go. You can do good. You have a second chance at life. Stop fighting us and let us help you and Mushroom."

"It's too late for me."

With that, Ghost freed her arm from Barry and then she went invisible. Barry tried to catch her but she was already gone. Barry just sat out onto the rooftop until Joe came out to talk to him.

"Caitlyn's gonna be fine. But Wells and Cisco can't seem to track Ghost and Mushroom." Joe stated.

"They don't want to be found. I should have been there when they got infected, I could have saved them." Barry sighs looking down. Joe put his hand on his shoulder.

"You didn't know. Besides you got struck by lightning while that ghost and Mushroom fused. You couldn't have saved them. You can't save them all the time but I know you'll be able to save them from this." Joe says. Barry looks at him

"How are you so sure of that?"

"Because I know you Barry. And I know you have always been able to save them."

"Well, when I found Mushroom again, I'll do everything in my power to bring her back."

Over at the haunted house, Ghost was looking out the window from her bedroom. "We'll meet again, Flash."

15 years ago. The West house

Mushroom at the age of 11 ran into the West house and hid behind Barry was 12. He looked at them concerned and saw they were covered in bruises and had a bloody nose. His eyes widened as he gently wiped the blood away.

"Mushroom? What happened?" Barry asked.

"People were making fun of my name again..." Mushroom answered and looked down. Barry hugged them.

"I still think Mushroom is a great name."

Mushroom sniffed, "At least one person does."

"Hey, Iris thinks it's cool. Besides, those people are morons." Barry stated.. Mushroom chuckled a bit making Barry smile.

"Thanks Barry. You're the best brother."

"And you're the best sister'

Central City Police Department present day

Joe and Barry came into the police department when they saw a mother and daughter talking to Eddie. They went over to talk to him. "Eddie, what's going on?" Joe asked.

"These two came into the station terrified. The little girl said that she saw a woman with black eyes show up in her room and scared the poor thing." Eddie answered.

"Ghost." Barry stated.

"Eddie, you remember me telling you about Barry's sister, Mushroom? That ghost is them. They got hit by the explosion and now they are fused to this ghost who just loves causing chaos." Joe explained.

"Your sister is a meta?" Eddie asks. Barry nods.

"Apparently." Barry sighs.

"Well can't you convince her-"

"Them" Joe cuts off. Eddie nods.

"Them to not do this?"

"We've already tried. It's proving difficult with Ghost being the one mostly in control" Barry says. Eddie opened his mouth to ask something before closing it and shaking his head, deciding not to ask.

"We know where they are hiding. But now we need to figure out where Ghost will strike next." Joe said.

Just then Captain Singh showed up and told them that the ghost was at Jitters, terrorizing the customers. Joe told Singh that he and Eddie will head over there right now. Barry just nodded and ran out.

At Jitters

Ghost was in Jitters throwing glass, flipping tables and overall just causing havoc. She laughed, her eerie laugh echoing a bit. The Flash ran in yelling at her to stop. Ghost groaned and looked over.

"You again Flash? I guess you really won't give up." Ghost said.

"I know you're still in there sis, please fight her." Flash begged.

"Ugg! Again with the begging. Give up Flash. The sweet little sister you knew is gone, there is only Ghost."

"I am not going to give up on you. I never have and never will."

Ghost looked away as she grabbed a glass but she was hesitating. The Flash walked over and grabbed the glass as Ghost's eyes turned white. He smiled.

"There they are." He smiles. Mushroom looked at him and hugged him tightly.

At S.T. A. R. Labs

Barry took Mushroom back to the lab to check if she had any injuries and thankfully she was clear. "So no one else got hurt? Right?" Mushroom asked.

"The place is mostly trashed but no one was hurt." Joe stated.

"So what happens now?" Mushroom asked Barry.

"That's up to you. I can train you to keep control and maybe you could be a hero like me." Barry suggested.

"And here I thought you were going to be protective and just help me control it."

"No." Barry chuckled. "If you want to be a hero I will allow you too" Mushroom smiles and nods.

"Let's just focus on me and Ghost controlling my abilities and maybe getting along first."

"Yeah. We can focus on that first"

"I still think Phantom Menace is better than Ghost."

"You know I can still just have Ghost come out and throw you across the room." Mushroom stated with a smirk.

"On second thought, Ghost is perfect." Cisco said with his hands in a surrender pose. Caitlyn and Barry chuckle.