[mare clauseum / closed sea]

"Rise and shine, lovebirds." A voice ripped through the fabric of Tessa's sleep, causing her to groan softly and absentmindedly scooch back to Kaden's side.

A groan came from the voice, and the next thing Tessa knew was that a pillow had whacked her in the face. Her eyes flew open and her gaze settled upon Mark, who was blinking at Tessa with impertinence.

"What?" She croaked, fighting a yawn. She looked beside her to see Kaden, still sound asleep, and memories of how she had gotten into that position flooded her mind.

"Yeah," Mark said blankly, although a smirk was laced onto his lips. Tessa rolled her eyes; the son of Iris would never let either of them live this down.

She pushed off of the couch, careful not to wake Kaden, who had substituted the pillow Mark had thrown for Tessa. She had hardly felt him beside her as she slept, only aware of the hand that held her loosely to him throughout the night. The memory made her heart flutter.

"Do I want to know?" Mark asked, wiggling his eyebrows suggestively.

Tessa stifled a groan. "It wasn't like that. We were both up and we just crashed."

"Yeah, okay, sure." Mark smirked, running a hand through his dark hair. He sauntered over to the kitchenette, grabbing a bottle of water. "So what's the plan of attack for today?"

Tessa narrowed her eyes, watching the son of Iris carefully. "Why are you in such a peppy mood? Yesterday you could hardly look at us."

"I have no idea what you're talking about," Mark said airily, taking a sip from his bottle. He glanced at Tessa as he did, and his facade fell. "Oh, alright."

"Spill." Tessa folded her arms, leaning against the wall.

Mark exhaled. 'It's just...you know how my dad summoned me yesterday, right? Well, I didn't expect it to turn out how it did. I mean, I love my dad and I visit him every summer but yesterday was just...different.

"I spent most of the time in his office, waiting for him to come back from some meeting. When he finally did come back, he didn't even bother trying to catch up or ask if I was alright. One look at me and his face fell, and he said he had something to give me tonight that would help on our quest. Then, he made me leave." Mark's gaze was distant, and Tessa could almost see the gears turning in his head as he tried to piece together what had happened into some logical explanation.

Tessa's features softened. "I'm sure he has good intentions, Mark. Our mortal parents...they know that as demigods, we're awaiting danger at all times. In times like these, they've only got a couple of minutes to say what they need to, because if they don't---" Tessa choked up, memories of her mother's last words to her echoing in her ears.

Mark met her gaze and hopped off of where he sat on the counter. He reached for Tessa but she shook her head. "I'm fine." She took a breath. "My point, Mark, is that everything will turn out okay with your dad. He'll give you this gift and we'll figure out what to do from there."

For a moment, everything was silent. Thirty seconds. A minute.

"Yeah," Mark said at last, his voice hardly above a whisper. "We will."

Tessa smiled softly at her best friend, then pulled him in for a hug. The two embraced for a moment, silently consoling one another that everything would turn out alright, even though optimism was the last thing on Tessa's mind.

"Hey, party people." Someone knocked on the kitchen wall. Tessa pulled away from Mark to spot Reese, a boyish grin on his face and his blue eyes shimmering with the energy that only an ADHD demigod could possess this early in the morning. "Ready to take on the world?"

Tessa gave the son of Apollo a look. "Not you too." She shoved past him, a laugh in her voice.

Judging from the sounds coming from the girl's bedroom and the boy's bathroom, Dale and Kaden had both awoken as well. If Tessa pretended hard enough, she could imagine that she and her friends were simply on a summer getaway and nothing more. The thought lifted her spirits.

Tessa approached the large ceiling to floor windows spanning the central room. She gazed out at the shore of the Pacific Ocean, at the surfers and swimmers who had already begun their activities as soon as the sun rose. The sound of the camaraderie and of the waves crashing against the shore resonated with Tessa like a siren's song, beckoning her to come closer.

"Hey, does anyone want to go with me to the beach?" She called, her eyes still on the cerulean waves glittering in the sunlight.

"I'd love to," Kaden chimed, emerging from the bathroom. "But we're running low on food so I'll be taking these two on a raid of the nearest grocery store." He jerked his thumb over to Mark and Reese, who arguing over what to include on a shopping list.

Tessa met Kaden's gaze and as if in sync, they both blushed in realization of what had happened. She wanted to speak to him, to ask him again if he was alright, considering what he had told her. However, Dale shook her out of her reverie.

"I'll go with you, Tessa," She offered, tying an elastic around her fishtail braid.

"Then let's go." Tessa smiled. She made sure Tempest was stuck in her pocket before heading out with Dale, leaving the boys behind.

~~

Tessa shut her eyes, basking in the sunlight as she stood ankle-deep in the water. The tide swept in around her, sending another pulse of energy into her body with every current. She felt more alive than she had in days, standing in her father's domain. Everything seemed to drown out around her, save for the sound of the waves in time with her own heartbeat.

"Enjoying yourself, Ariel?" Dale laughed, seated on the sand a few feet away.

Tessa opened her eyes, now reflecting the surface of the sea, and gave a sarcastic look to Dale. "Very much so, actually." She stuck her nose in the air, before erupting into giggles with her best friend.

The daughter of Demeter looked around, a casual smile on her lips. "So aside from your enjoyment, why are we here?" 

Tessa pursed her lips, gazing out to sea. "I just got this feeling," she mused. "Something's waiting for me."

"Your dad?" Dale questioned. "Maybe it's him."

Tessa shook her head, running a hand through her dark hair. "Maybe, but I doubt it. He visited me before I went on the quest, so I don't think he'd risk Zeus' wrath to see me again."

"Then who could it be?"

Tessa shrugged. "Only one way to find out."

Before Dale could stop her, Tessa sprinted into the sea, diving into the next wave crest. Instantly, her senses sharpened as she looked around underwater. She could see every current, every wave, every animal as it approached her. She could hear their thoughts, and smiled in amusement as they revered her while she swam by.

Tessa reached the edge of the reef, where the sunlight zone met the twilight zone, and stared down at the dark depths below. She wondered if her abilities would protect her from the ocean's pressure down that deep, but before she could get the urge to test it out, the water before her rippled.

"I see you've answered my call, Thalassa," A melodious voice said. Out of the rippling currents, like sunlight shining through the water, a figure materialized. She was hardly solid, dark hair like Tessa's billowing in the water around her. She wore an Ancient Greek chiton that shimmered like water had crystallized to form the fabric. Her eyes were pure gems, but her smile was warm.

"Who are you?" Tessa asked, her own voice sounding faraway in the water.

"I am one of the Nereids, child. We serve in your father's court, and we have watched over you on your journey. You have come quite some distance, haven't you?" The woman spoke, her voice as soft as a babbling brook.

"That's an understatement," Tessa managed sheepishly. "Why did you bring me here?"

The nereid's crystalline eyes darkened, the way Aphrodite's had before she had given Tessa the news regarding her mother. "You seek to find and defeat Deimos, yes?"

Tessa nodded.

"Then there is something you must know about his location. Deimos seeks to lure you into a trap by using your abilities against you. As a daughter of Poseidon, you can manipulate fresh and salt water to your heart's desire, but this cannot be your only resource of strength, for Deimos will use it against you." The nereid continued.

"What? But that's insane, if I can control it, no one can sever that control from me," Tessa argued.

"No, but he can use your fears to get you to sever your own control. Your abilities prevent you from the one thing all other demigods would endure should they go without air in water, but Deimos will try his hardest to strip you of that protection. Do you understand?"

Tessa blinked in disbelief. All her life, she had never feared drowning, but how could Deimos make her fear something that would never happen?

"Yes," she said at last, her voice gravelly. "I understand."

The nereid's eyes flickered. "Good. My freshwater sisters will do their best to keep you safe, should you end up in their territory during your battle with Deimos." Her form flickered, and she sighed. "I must return soon. But before I go, one last piece of advice. Seek out your brother in San Francisco. He has witnessed the last of Deimos' panics, and can offer you aid as to how to defeat him."

"What? I don't have a brother!" Tessa exclaimed.

The nereid smiled, although her form continued to fade. "You do, Thalassa. You just haven't met him yet, although you know who he is. The power of the sea flows through both of your veins, and the courage in both of your hearts will result in your story serving the test of the time just like his has. Farewell."

Tessa reached out but the nymph dissolved, leaving her standing on the precipice of her fate. With a heavy heart, Tessa turned and headed back to shore, her mind racing. And as she did, she found herself holding her breath.

~~

"So let me get this straight." Reese held up a hand, leaning against the elevator wall. "Deimos is going to try to drown you, and in order to stop him, we have to seek out your long lost brother?"

"In a nutshell." Tessa exhaled. She, Reese, Dale, Kaden, and Mark stood in the elevator, headed to dinner that night with Mark's dad. The boys had only gotten back a little while before, having gotten lost in Los Angeles as they searched for supplies. When they did return, Tessa filled them all in on what the nereid told her as they headed out.

"That's bogus, that's what that is." Mark wrinkled his nose. "How can you drown? Isn't that, like, physically impossible for a child of Poseidon?"

"That's what I thought, but the nereid made it seem like Deimos would somehow use his powers over fear to make me fear it, and therefore make it happen." She took a shaky breath. "Weird, huh?"

"And what's this about your brother? Is he a demigod?" Kaden asked, his eyebrows knit together. "What did the nereid say about him exactly?"

The nereid's words still resonated throughout Tessa, and she was getting tired of all of these hints and tips about her quest.

"She said that the power of the sea flows through us both, which I assume means his dad's Poseidon as well, and that we could find him in San Francisco," Tessa recalled.

Before anyone could make anything of it, the elevator doors opened, revealing the family about to join them on the way down. Tessa sighed, turning to her friends. "We'll talk about it later," She hissed to them quickly. The family filtered into the elevator, and the demigods fell to silence.

Thankfully, they reached the main floor quickly, and as soon as the doors opened, Tessa ushered herself out, her friends in tow. The family went one direction, and she and the others headed another.

"Alright, Mark, lead the way." Kaden clapped the son of Iris on the shoulder, who jumped.

Mark looked frazzled enough, but forged his way through the lobby. He led the demigods to the restaurant his father had asked them to meet in, and stopped outside of it. "Here it is," He waved a hand lazily at the entrance.

"Do we have a plan?" Reese asked, eyeing the restaurant carefully.

"We find Mark's dad and have a lovely chat over the possibility of our death while eating fine cuisine." Tessa decided. And with that, they headed into the restaurant.

There was a line of people waiting for their reservation to be called, but Mark wove through them until he reached the counter. He muttered something to the hostess and instantly, her eyes widened. She led Mark and the others through the restaurant and around various waiters until she approached a booth in the back of the restaurant.

Seated in the booth was a middle aged Asian man, dressed in a business suit. He had a suede black box sitting across his lap, and was bouncing his foot anxiously on the glitzy obsidian floor of the restaurant.

"Mr. Akagi, your son," the hostess announced.

Mr. Akagi looked up and his eyes feel upon Mark instantly. "I'm glad you could make it," he said, a silky tone to his voice. "Please, take a seat, kids."

Tessa followed Mark, who scooted around the table and down the bench seat to sit beside his father. Dale crawled in beside her, followed by Kaden and then Reese. The five demigods looked at Mr. Akagi expectantly as the waiter approached, handing them all menus.

As everyone got to work on figuring out what to order, Tessa scanned the restaurant and Mark's father for any sign of danger. There didn't appear to be anyone suspicious lurking around the five-star eatery, but Tessa didn't want to get her hopes up. Even Mark's father looked relaxed, despite his nerves jumping off the radar as soon as they showed up.

The waiter returned moments after, and after they all placed their orders, Tessa glanced at Mark's father. "So, Mr. Akagi, what's all of this about?"

He met Tessa's gaze and just as quickly looked away. "Quick to jump to business, I see."

"We're demigods, we kind of have to be quick or else we'll be killed. Any information you may have that can aid us in our journey would be much appreciated." Tessa smiled.

Mark's father took a breath. "While I'm only a mortal, I can see through what you demigods call the Mist. Iris noticed me for this, and after Mark was born, she allowed me to always be able to see the mythological as it truly was. No god or monster can veil their true form from me any longer, but this has been a burden rather than a blessing lately.

"A few weeks ago, a man entered the hotel. He didn't look quite right at first, and I was able to recognize him for who he truly was. He didn't give me a name, but I knew he was a god. The way his power radiated off of him was taking effect to the people nearby. He approached me nonetheless and asked about Mark." Mr. Akagi took a breath.

"He asked where Mark was, and when I didn't tell him, he simply walked out, vowing he would find him sooner or later. Later that day, a mass panic attack erupted a block down the street."

"Deimos," Reese interjected. "He came here looking for Mark. But why?"

The answer came to Tessa faster than she cared to admit. It seemed it arrived to Kaden as well. They locked eyes. "Chiron."

"What about Chiron?" Dale asked, her gold eyes glowing in the dim light of the restaurant.

"When Chiron assigned us to the night watch, he told us that the malevolent forces were causing the campers already on the watch to witness their greatest fears," Kaden explained.

"And when Phobos told us that those forces and the fire were caused by Deimos, he also said that when we would face Deimos, he'd make us susceptible to our own fears unless we got his sphere of power," Tessa continued, the adrenaline beginning to pump through her veins.

Reese snapped his fingers. "Which explains why the Nereid would tell Tessa that he would try to drown her."

"And why Deimos himself would come looking for Mark before attacking camp, inciting all of this," Dale added.

"And when he couldn't break through camp, he backed off and then the quest was issued." Mark concluded.

Mr. Akagi blinked. "I'm sorry, what just happened here?"

Tessa took a breath. "It means that our good friend, the god of terror, has been further wound up in his tricks than we had hoped. He plans to find out all of our darkest fears and use them against us to stop us from defeating him. By destroying us with our own minds, it would force the Olympians into civil war to acknowledge his power."

"Unless we destroy his source of power, which takes the form of a spear," Mark explained to his dad. "Please tell me that whatever you have to give me is some way we can stop this bozo."

Mr. Akagi blinked again, no doubt trying to absorb all of the information about this other world his son was a part of. "Unfortunately, no." He hefted the black box, setting it down on the table. "However, it might come in handy, should you do any fighting."

"We will," Reese guaranteed. "Most likely on an hourly basis."

Mark reached for the box but Mr. Akagi slapped his hand down on top of the lid just as quickly. "Don't open it here. I'm sure the other mortals would lose their mind if the Mist made them see an alternate version of what's inside. When you head back to your suite." He patted his son's hand and looked up at the other half-bloods. "There's more."

"Hit us with it." Kaden sighed, leaning back against the scarlet cushions of the booth.

"Because I live on the opposite side of the country, Iris also has granted me the ability to look in on Camp Half-Blood to make sure Mark was safe from time to time. However, as soon as she brought word that he left, she gave me the task to make sure the camp was stable," Mr. Akagi said, knitting his fingers together.

"Why does mom give you all the cool powers?" Mark grumbled.

"You literally can manipulate color and light and turn invisible. Hush up," Dale chided.

"Anyways," Mark's father continued. "I've been watching your training camp, and while everything appears to be normal, something is going wrong. I'm not sure what, but the campers have seemed...suspicious. They wear their armor more than usual, and normal activities have halted to battle training. I'm not sure what could cause such changes, but I figured you five might have an inkling."

Tessa racked her brain as a pang of fear resonated in her heart. If something was about to happen back at camp, who would be there to protect her friends? Flynn, Amelie, Calum and Nova...she needed to contact them, to talk to them, ask them what was going on.

But part of her told her that she already knew.

"The spy," She breathed. "It's gotta be the spy."

"What spy?" Reese asked, running a hand through his blond hair.

"When Kaden and I met with Aphrodite back in Vegas, she told us that Deimos had a spy inside camp. No one knows who it is, only that they've been causing turmoil around the borders and that when Deimos gives them the word, they had the ability to try to destroy camp," Tessa explained, her words nearly sliding into one another as she spoke. She needed to breathe before she lost it entirely. No one would mess with her home, not if she could do anything about it.

"Great." Dale slumped back into the booth. "Just great."

Tessa took a shaky breath, despite her throat feeling like it was about to close in on itself. "Thank you for your information, Mr. Akagi. It'll come in handy. Now if you'll excuse us."

The demigods began to file out of the booth seat, all on edge. Mark grabbed the box off the table, holding it as if it were a bomb. He, Tessa, and Dale made a beeline for the exit.

"Wait, what about the food?" Reese called from behind them, pointing to the confused waiter who was about to unveil their meals.

"Not now," Kaden scolded, grabbing his best friend by the wrist and lugging him after Tessa, Dale, and Mark.

The demigods surged out of the restaurant, hearts beating rapidly in sync as they made their way back up to their suite. They stood silently in the elevator, the burden they all carried looming over them like a storm about to break. Not only were their own lives at risk, but the lives of their friends back at camp and those of the world that would become a battleground should Deimos succeed were too.

~~

"We've gotta go back," Tessa decided, pacing the floor in front of the windows. The moon hung over the ocean, the only source of light in the darkness.

"We can't, Tessa, and you know that," Reese countered from his spot on the couch. "All of this would be for nothing. Besides, who's to say that upon seeing us come back, the spy would carry out their turmoil anyways?"

"Who's to say that now that Deimos is coming after us, he won't finish us off before we catch him first and let his spy destroy camp?" Tessa snapped, her voice catching.

Kaden stood up, running a hand through his tousled hair. "Tessa, we're so close to defeating Deimos. That's the safest option for now. We continue on the quest, defeat this guy, and that way, the spy won't be able to do anything. We could get back to camp and weed them out. Won't be too hard to find out who the backstabbing coward is."

"Kaden's right," Dale said, her voice calm. "We can do this."

Tessa took a deep breath, focusing on the lull of the sea outside. The Nereid's advice came to mind, and she found the strength to speak again. "Then we have to head to San Francisco. The Nereid said that he witnessed Deimos's last fiasco, and he'd be able to help us with defeating him."

"I'm down for more firepower any day." Mark clapped his hands together. "Speaking of which, time to see what good old Akagi Claus decided to get me."

He headed to the dining room table, where the map of California was still sprawled. The black suede box sat atop it like a paperweight, covering most of the map. Mark took a breath and lifted the lid off the box, his almond eyes going wide with amazement.

"He didn't." Mark breathed.

"What?" Tessa asked.

In response, Mark lifted the celestial bronze katana out of the box. It glinted wickedly in the moonlight, and Mark's actions seemed to be slowed down as he tested the blade out, slicing it through the room.

"This thing has been in my family for centuries." Mark's voice sounded small. "My dad told me never to touch it, that I'd hurt myself if I didn't know how to use it."

"Well, good thing you do." Reese shrugged. Then his eyes widened. "You do, right?"

Mark gave the son of Apollo a look. "Yes, I do. I don't only excel in fighting with knives, you know." His gaze returned back to the blade, and he set it down carefully as he extracted the sheath from the red velvet insides of the box.

"Don't slash the upholstery, Mark," Tessa teased. "Your dad may be lending us this room, but I don't think he'd be happy if his son used his gift to destroy his hotel."

Mark made a face. "Yeah, yeah," He sheathed the katana and set it down beside its box. "Speaking of, are we still on schedule? Are we leaving for San Francisco tomorrow?"

Tessa looked around, taking the looks of everyone else as a general consensus. "Doesn't look like we have another choice. See you all in the morning, then." She turned on her heel and started for her room.

"Wait, Tessa, we still don't know who your brother is or how to find him," Dale protested.

Tessa stopped in her tracks. She'd forgotten about that little detail. She turned around, facing her friends. "How many demigod children of Poseidon are there?"

"Probably a lot that are still unclaimed," Mark countered from the dining room table.

The courage in both of your hearts will result in your story serving the test of the time just like his has. The nereid's words surfaced in Tessa's mind and an idea began to formulate.

"He's famous," Tessa muttered. "My brother, this son of Poseidon, has a story that's served the test of time."

Kaden knit his eyebrows. "Where'd you get that idea?"

"The Nereid, she said I would go down in history just like he did. So he must be older too..." Tessa tried desperately to come up with some identity to her estranged brother, but found nothing. She sighed. "We'll cross that bridge when we get there. Good night, guys."

She turned on her heel and headed to her room. As soon as she was ready for bed, she collapsed onto the blankets and was whisked away into a dream the second she shut her eyes.

~~

Tessa stood inside the arena back at camp, the sun directly overhead as she looked around. She appeared to be invisible, which was just as well, considering two figures moved into her vision from the entrance. Tessa peered closer, and lit up at seeing Reese's twin brother, Flynn, approach the center of the arena with Amelie at his side.

"Come on, Ams, one more time," Flynn pleaded, clasping his hands together desperately.

"Flynn, I told you I'm not good at using my powers," Amelie mumbled. Her dark hair was tied into its typical braid, but she wore her armor just like Flynn was. Everything Mr. Akagi had told Tessa about the campers being prepared for battle was coming to pass.

"But you did great earlier today!" Flynn exclaimed, a grin on his face.

"I nearly turned Calum into a hedgehog! Again!" Amelie rebuffed. Her face was red, and Tessa couldn't tell if it was from anger or embarrassment. Probably the latter, considering Amelie never got angry at anyone.

"Pleeeeeeeease?" Flynn pleaded. "It's for the good of the camp and you know that."

Amelie looked into Flynn's blue eyes and sighed. "Fine," she admitted in defeat. Flynn cheered as the daughter of Hecate prepared herself.

She outstretched her arms, shutting her eyes. Just as the beginnings of magic began to form around her hands, an explosion in the distance made both demigods jump.

Tessa turned and sure enough, a plume of black smoke billowed into the sky in the distance. She glanced back at Flynn and Amelie, but her friends had already bolted to see what had happened.

The dream shifted and this time, Tessa watched as her thirteen-year-old-self sat in mythology class at camp. She, as well as the other newcomers from that summer, listened in as Chiron explained the various heroes he had trained over time. He had told them about all of their stories, and Tessa watched her past self as she began to develop the persona she still hid behind to that day.

"And so, just like Hercules, and Odysseus, and Theseus, will you young half-bloods grow to become the greatest heroes of your time. Your stories will be written in the skies just as theirs have been," Chiron concluded his lecture.

One half-blood raised her hand eagerly, eyes bright with fascination. "Who was Theseus' godly parent? I really like his story."

Chiron smiled at the girl before directing his attention to where Tessa sat in the back of class. "Poseidon," he answered. "Theseus was the son of Poseidon, if not the most famous son of Poseidon of all time."

Everyone turned to look at Tessa and she watched herself give her signature smirk, the one that labeled her a troublemaker throughout her life.

"Theseus might be the greatest son of Poseidon, but I'll be the greatest daughter of Poseidon that the world has ever known." She announced.

The dream began to fade, and the last thing Tessa saw was Chiron's grim smile, as if he knew her destiny and it would only be filled with pain.