A/N: A random plot bunny that attacked and wouldn't leave until I wrote it. It feels good writing long pieces again. o3o

Warnings: OCs / Slash / Incest / Possible OOCness. Read at your own discretion.


Charlie was, by nature, a logical person. He didn't believe in anything if it couldn't be proved by numbers, statistics, or logic. It was a part of him he couldn't shut off, no matter what he tried to do. People tried to get him to believe in the supernatural or paranormal, but even after having an experience of seeing his deceased mother in his dreams, Charlie simply didn't believe those things existed.

So, when he started getting sick and Victoria told him that it was because of something called a "soul cluster", he didn't believe her. Those things don't exist, he told her. I just have the flu.

So why, she countered, is your brother sick too?

That threw him, because he had no idea Don was. His brother always kept up appearances, bringing down bad guys and interrogating them to spill on what their crimes were. Even when they were kids, if Don was sick, he'd brush it off and act like nothing was wrong. It was something that grew to adulthood, Charlie guesses. No, he does more than guess. He knows that's how Don Eppes functions.

How did this soul cluster thing start, he questions Victoria one day when he was feeling particularly miserable. His head hurt, his chest was congested, and he went through almost five boxes of Kleenex in less than four hours. He started to notice that Don was paler than usual and his movements were more sluggish, but still, he denies the logic that Victoria throws at him. Because, he says, such a thing doesn't exist. It's like those who believe in magic; there was always a logical explanation behind the illusions and tricks that "magicians" used.

Maybe a flu bug was going around and they happened to catch it at the same time. It was highly probable; they worked in the same space almost every day and both were in contact in places where germs could easily spread.

His mind completely ignores the fact that everyone around them was fine and it was solely them who were sick.

Well, Victoria says when he asks, her lips curling upwards to a smile. Damn her and her cocky attitude, Charlie mutters inwardly, coughing in his fist and ignoring the look the older woman sends his way. It happens when one person protects the other from dying, she says. Did anything like that happen recently?

Vaguely, he remembers something like that, but his mind refuses to acknowledge when it was. Maybe it was still in denial of the whole "soul cluster" analogy, but it would be quite helpful if he remembered how long ago it was in case such a thing did exist. The more his mind thinks on it, the more he realizes that it's highly unlikely that a flu bug was going around, because finally his genius brain acknowledged the fact that he and his brother were the only ones who caught the mysterious illness.

There was something like that, he offers after a few minutes of silence pass between them. Victoria gives him one of her knowing smirks and pats his shoulder, urging him to remember and open himself to the bond. He questions her; how do you know so much about these types of things, but she smiles and says she has more experience than most would think she does.

Lying on his bed, still having no more answers, the youngest Eppes drifts off to sleep, trying to understand what was going on and how to fix it.

-v-

It was a regular day; nothing suggested that it would be abnormal. Charlie walks in the FBI office, humming a tune to a song that his favorite band put out a few days ago, and greets the agents who say a casual hello to him as he passes them. He goes in one of the rooms and stares at the whiteboard, equations coming to his mind about the latest case. Flexing his hand, he takes a marker and begins writing, completely oblivious to what was going on around him.

He hears the door open, but ignores it as he continues writing. His eyes widen slightly when he hears the cock of a gun, but he figures it was an agent checking their sights, so he keeps at what he was doing. A pressure against his head makes him stop and he glances behind his shoulder, being greeted with a psychotic smirk.

"You're my ticket to salvation, little Eppes," the man purrs, his voice sounding like silk but menacing at the same time. Charlie recognizes the voice; agent Davis of the tactical division. Something always struck him as odd about the agent, but he didn't say anything to anyone, thinking that it was his poor people skills that gave him the wrong impression. It wouldn't be the first time that happened.

"Salvation?" Charlie questions, raising his hands and turning around. Davis's eyes scan him and he feels like a bug under a microscope. "What do you mean?"

"I mean-…"

"Drop your weapon and put your hands behind your head!"

Davis turns, bringing Charlie with him, pressing his gun against the professor's temple. "No! He's going to save my soul from corruption and I won't let you take him from me!"

"Easy, agent. We want to resolve this peacefully. What do you want?" Don asks, making eye contact with the psychotic agent and then his brother. It's going to be okay, his eyes say. I'll protect you.

"I want to be saved and they told me he's going to do that for me!" Davis yells, his finger that was on the trigger trembling. "Just let us go and no one will have to be hurt."

"We can't do that," Megan cuts in, coming in from the other side. David and Colby flank her, all their guns pointed at one they used to consider a colleague. She looks at Don, nods, and he nods back, moving out of the room. For a moment Charlie wonders what's happening, then a loud bang comes and he's dropped on the ground. "Suspect down!"

Charlie wraps his arms around himself, clenching his teeth together and doing his best to compose his shuddering. All too familiar arms wrap around him and he buries himself in his brother's warmth, trying his hardest to not let the tears in his eyes fall. Charlie feels a weight on his head and Don's voice tell him it's okay, let everything go, and that's all he needs to break the dam on his emotions. Shuddering with sobs, he clenches Don's shirt as if it's a lifeline and mumbles about how sorry he is.

It's fine, comes the reassuring, warm voice. I'll always protect you.

-v-

Charlie bolts upright, shaking himself and another cough escapes his system. Of course, that's what happened. Davis hadn't been killed, just stunned enough so they could apprehend him, and during a psychiatric assessment, it was determined that the agent had PTSD from one his busts a few months back where it went sour.

The sunlight pours in the window, and Charlie moans slightly, getting out of bed and changing his clothes for the day. He answers his phone when it rings and goes to the FBI office half an hour later, surprised to find that his brother's desk was empty. Don never missed work, he thinks to himself, tilting his head as he goes towards where Megan sits.

"Where's Don?"

Megan looks up at him and gives off a little sigh. "He took the day off. He sounded terrible. He's looked terrible for the past week. You don't look too good either," the agent adds as an afterthought, raising both eyebrows. "Why don't you go home? We'll handle things without your expertise for the day."

Victoria passes them with an all knowing look in her eyes. "I'll drive you to his place and I'll catch a cab back to work," she offers, taking Charlie's arm and moving towards the door. "I'll be back soon, Meg. Don't start the party without me."

"It's Megan," Megan says with humor, but she waves them off and returns to her paperwork.

"I told you," Victoria says as she gets in Charlie's Prius and starts off once the mathematician gets in. "I've never seen bond sickness get this bad in a long time."

"Bond sickness?" Charlie questions, shaking his head to rid himself of the dizziness that swamped his system. "What's that?"

"What you and Donnie-boy are experiencing," Victoria says simply, turning off the radio so they can have a proper conversation. "It's where a soul bond forms, but one rejects it and causes both parties to become sick. The one who's repressed gets sicker than the one doing the repressing." Here she looks at him and sighs. "If you're this bad, imagine what ol' Donnie-boy looks like."

Charlie feels his heart clench. He never wanted to put Don through anything like this. Apparently he fell flat on his face regarding that because here he was, putting Don through something that was making them both sick to the point of his brother skipping work, something he never did in his life. "Will he be okay if I stop repressing it?"

"That's a start," the older woman replies, stopping in front of Don's apartment. "You have to kiss him to show that you've stopped. After that, don't stray too far from each other. I know it might raise eyebrows, but I've heard of bond sickness killing if it's repressed too long. You two are dangerously close to that, I can sense it."

Great, Charlie thinks. Not only did I succeed in making us both sick, I almost killed us. "I guess I shouldn't waste any time?" he jokes weakly, getting out of his Prius and making his way up the stairs. "Thanks, Victoria. I'll … try to do something about this."

"Anytime, Charlie," she replies, taking out her phone as he makes his way in the apartment building. "Good luck," he hears her say before he shuts the door.

Charlie makes his way to the elevator, pressing the button to Don's floor. He takes out some Kleenex, blowing his nose and throwing the soiled tissues in the trash once it stops and he gets out. He walks, stopping in front of his brother's door and testing it. Locked, of course. Charlie takes out his key, opening the door and shutting it gently behind him. The whole apartment was quiet, something foreign to the youngest Eppes. Don was always moving around or doing something in here, not the absolute stillness that resonated through the space.

Shivering slightly, the professor makes his way to the bedroom, where the lights are off and the blinds cover the window. "Don?" he whispers, not wanting to wake his brother in case he was asleep, but also wanting to know how bad Don was.

"…Mm?" his brother's voice comes, sounding strained and laced with sickness. Charlie winces. Don sounded like death warmed over. No wonder he took the day off, he thinks. "S'that you, Chuck?"

"Don't call me," a cough, "Chuck."

That gets a reaction. Charlie can see the bed rustling before a head peeks out from underneath the covers. "Don't tell me you're sick too," Don groans and Charlie can barely make out his brother rubbing his eyes. "What's goin' around, some kind of bug?"

"Um … no. No one else is sick except us," Charlie replies, maneuvering around the bed to sit on the end. "Have you ever heard of a soul cluster before?"

"What, is that like soulmates? That stuff exists in movies and children's fairytales, not real life."

"I thought that too, and for a while I thought there was a logical explanation to this whole scenario. But … Victoria spoke to me about it and I realized hers was the logic I was looking for." Charlie pauses for a moment, unsure of what to do, but then he gives an inward shrug and moves so he's kneeling in front of the bed. "I'm sorry about this, but it's the only way to make us not sick."

With that said, he presses his lips against his brother's, feeling Don tense almost instantly but then relax and return it with fervor. After a couple minutes pass, they break for air and Charlie immediately feels lighter, as if a huge weight's been lifted off his shoulders. Judging by the look on Don's face, he guesses that it had the same effect on him as well.

"That was…" Don pauses. "Different," is the word he settles on, causing surprised laughter to erupt from Charlie's mouth. "What? It was. It's illegal and if anyone found out about it, we'd both be royally screwed. But … I guess we both need this, huh?"

Charlie simply nods and wraps his arms around his brother, nuzzling his face in the junction of Don's neck and shoulder. He smiles faintly when arms wrap around him and hold him close, the sickness he was feeling minutes before seeming to dissipate the longer he was held in Don's arms. Was he always this comforting and warm?, the youngest Eppes thinks to himself, and he nods, smiling against Don's skin as he hears his elder brother hum some nameless tune.

Yes, he always was, Charlie clarifies for himself, letting out a little laugh. But I just didn't realize it.