The Eppes brothers were edgy.

Charlie was edgy because Amita, his thesis advisee and somewhat potential love interest, was leaving for an assistant professorship at Harvard University. It was a good, nay, a brilliant, opportunity, but the hint of what might have been between them nagged at his mind, and even more so the consequent thought that he would be so arrogant as to expect Amita to stay just for him. And, well, the numbers trying to short-circuit his brain weren't helping, but he'd been dealing with that since he was three years old.

Don was edgy because the crook they'd been chasing hadn't been caught yet and his brother was constantly distracted but people were going to die, so if he could please get his mind off his failing love life and focus on the case, that would be great, thanks. It wasn't as if he was the only one who'd ever lost a girl before the relationship even took off and with his social skills it was a miracle Amita even stayed this long.

David, Colby, and Megan watched the two brothers warily. Don was pacing, clenching and un-clenching his fists, and Charlie's eyes were darting back and forth across his laptop screen as his fingers flew over the keys. Every so often, Charlie's eyes would blank out, but he'd shake his head and start working again, just as Don threw him an aggravated look. A storm was brewing between the two of them, and none of the other three wanted to be caught in the crossfire.

"What have you got, Charlie?" Don asked eventually.

Charlie shook his head without pausing his work. "I need more time, Don. This algorithm will take at least four hours to finish."

"Four hours?!" Done exploded, "We don't have four hours, Charlie, we barely have two! Can't you go any faster?"

Charlie glanced up, tense, his eyes flashing angrily. "I'm doing the best I can, Don."

"Best isn't good enough! Charlie, innocent people are going to die! Do you understand that?!"

Megan, David, and Colby winced. Every agent under Don had been on the receiving end of the 'best isn't good enough' rant at least once in the middle of a tough case, but that was just how Don worked. He pushed his agents to their limits and beyond, but only if the situation called for it. He had to be tough to be an effective leader. The problem was, Charlie wasn't one of his agents.

Charlie's breath caught in his throat as he resisted the urge to snarl 'Innocent people die every day.' He knew his brother was only lashing out because the case frustrated him, because he'd taken this case to heart. No matter what he said to Charlie or his teammates, Don always took his cases to heart. That's what gave him his edge and drive to succeed.

Before Charlie could answer, however, his cell phone started vibrating. Receiving a frustrated nod from Don, Charlie flipped it open and answered.

"Eppes."

Charlie's face immediately closed off and he barked, "No," before closing his phone and tossing it back on the table. Ignoring the FBI agents' gazes, he resumed typing.

The phone started vibrating again. Charlie resolutely ignored it. He was not about sacrifice three months worth of sleep, not again.

"Charlie?" Colby ventured, "You going to get that?"

"If it's that important he'll call back," Charlie muttered tersely.

Ignoring the piercing gazes he knew were being directed his way, Charlie fished out a notebook and started scribbling out functions. The phone fell silent, before starting to vibrate again.

"Damn," Charlie cursed under his breath.

Jamming the phone between his shoulder and ear so that he could keep typing, Charlie said, "Eppes."

"If my answer hasn't changed in three years, what makes you think it's going to change in the thirty seconds since you last called?"

Charlie froze for a moment, pure, unadulterated rage masking his face. Clenching his jaw and forcing his emotions back, he growled, "Start talking."

A few minutes in, Charlie froze again, the oh-my-god-I'm-such-an-idiot kind of realization dawning across his features.

"Repeat that," he snapped, his fingers flying over the keys with renewed fervor.

Charlie pressed his lips together in a thin line, his breathing starting to sound forced. The rage was back in full force. He flipped to a new page in his notebook and started writing. A few minutes later, his pencil snapped in half.

"You know what? Fuck. You."

Charlie ended the call and ripped the page out of his notebook. Suddenly, it became all too clear that this man was indeed Don's brother. How many times had that same, tight expression adorned Don's face in the middle of a case.

"Here," Charlie said roughly as he pushed the paper towards Don, "Your perp, his address, the time of his next attack, his next victim, his next victim's address."

Don scanned the paper as David's eyebrows shot up. "You figured out all that with math? What happened to needing four hours?"

"I had an epiphany," Charlie replied testily.

"Yeah? Well, next time, could you get your epiphanies a little sooner?" Don muttered.

Charlie slammed his laptop shut and quickly packed away his things. Megan, who had stayed silent so far, asked quietly, "Charlie? Are you alright?"

Charlie shook his head. "Worry about your case, Megan."

Charlie had his hand around the doorknob when Don asked, "Whoa, whoa, wait, Charlie, where are you going?"

Charlie gripped the doorknob so tightly his knuckles turned white. Without looking back, he ground out, "Don, do me a favor. Don't come near me for the next three days."

And then he was gone.

There was a beat of silence as the four FBI agents wondered exactly what had happened with their mild-mannered mathematician before Don barked out his orders and they left to catch a criminal.

As usual, Charlie's information was solid. They caught the criminal, wrote up their reports and headed home for a well deserved crash. Well, Don, Megan, and David did. Colby decided to head over to a bar and relax with a few drinks.

The bar he frequented was a surprisingly respectable one, about a block away from his apartment. He sat down on a barstool and waved to the bartender, an elderly man with snow white hair and kind, dark eyes.

"The usual, Colby?"

"You got it, Mike," Colby replied with a tired grin. Mike was a rare sort; he listened to whatever problems his customers had and never said a word. He always seemed to know when someone just need to vent, when they needed advice, and what type of drink they needed for each occasion. In the year that Colby had been in LA, Mike had been one of his greatest supports.

Colby looked down at the drink Mike passed to him. "That's not my usual," he remarked.

"The lad down at the end got it for you," Mike replied, nodding to Colby's right.

Colby took a sip and looked over, promptly choking on his drink.

"Charlie?!"

Charlie raised his glass towards Colby with a small smile.

"Agent Granger," Charlie said mildly, "How lovely to see you here."

Colby raised an eyebrow. "Charlie, what are you doing here?"

Charlie looked at him as if he had asked what two added to two was. "Drinking, what did you expect? Oh, please... don't tell me you think I'm a monk like Don does."

Colby cleared his throat uncomfortably. In truth, he sort of did. Charlie was… well, a geek, to put it bluntly. The only things associated with him were chalk and numbers. The thought of him drinking or getting any action just seemed out of place.

Charlie burst out laughing. "You do, don't you?"

Colby shrugged and took another sip of his drink. It was pretty strong. Good, but strong.

"Never took you for the type."

Charlie smiled sadly and took a sip of his drink. "Makes the numbers go away, if only for a night."

Colby sat up, concerned. "What do you mean?"

Charlie waved his hand distractedly. "The numbers, formulas, equations all buzzing around in my head twenty-four-seven. There's only so much a person can take, y'know? Well, actually you don't, seeing as you're not the one who can't look at a glass of water without volume, density, rate formulas running through your head. That's why I'm always scribbling at a chalkboard, trying to get the numbers out of my head, in the hopes that maybe I'll get some peace, but for every formula I get out, another one takes its place in my mind. I come down here once a month to clear my head, recharge… Why am I telling you this, again?"

Colby's eyes widened as he listened to Charlie. He'd never really considered the cost of Charlie's genius. The math the other man worked on had always seemed like magic to him, but he'd never really thought about where the numbers came from.

"Does Don know?"

Charlie gulped down the rest of his drink, humming as it burned down his throat.

"Hmm… I think so. I remember running to him one night when I was little, begging him to make the numbers go away. I don't think he was too happy with being woken up at 2 in the morning. Hey, Mike! Can I get another one?"

Mike came over with a wary expression. "You sure, Charlie?"

Charlie scoffed, "I can still recite the Fibonacci sequence backwards from 96,151,855,463,018,422,468,774,568 and hold a coherent conversation. I'm not drunk enough."

Mike shook his head and left to make Charlie's drink. Colby raised an eyebrow and asked, "Charlie, how much have you had?"

"Not nearly enough."

"Charlie."

"What? You think I don't know what I'm doing? I've been doing this since I was 15 years old, and yes, I'm well aware what the legal drinking age in California is."

Colby's brow furrowed. "Didn't Don say that your mom went to Princeton with you? She let you go out drinking?"

Charlie laughed, the alcohol making it sound slightly hysterical. "I made Mom go home in the middle of my first semester. I wasn't fond of being made an escape for her marital problems."

"And here we all think you're emotionally inept."

Colby froze as soon as the words left his mouth. Damn, the alcohol was working on him faster than it was on Charlie and he'd only had one glass! Charlie just laughed again.

"I don't exactly have space in my head to deal with emotions, but even I could tell what my mother was doing was wrong. And college got easier when my mother wasn't picking me up from class."

Charlie started humming idly, a soft smile on his face. "You know, I can't listen to most music without trying to find patterns for the sound waves."

"Don't you listen to music while working?"

Charlie shook his head. "Nope. They're just sound-blocking… The numbers are starting to fade a little…"

Mike set down Charlie's drink, saying, "Here you go, Charlie. I called Derek. He should be here soon."

Charlie nodded and knocked back his drink. His eyes closed as liquid napalm burned down his esophagus. He almost missed Colby asking if he'd talked to anyone about his problem.

Charlie opened his eyes and turned back to his companion. "A psychiatrist, you mean? When I was younger, yes. All he did was prescribe some anti-anxiety pills… They tasted nasty and made me feel weird, so I stopped taking them after the first time. And now that I'm older, the country can't afford to dampen my mind with medications."

The last sentence was said with a surprising amount of bitterness, and Charlie's words were starting to slur ever so slightly.

"You never know how much of a patriot you really are until you choose your country over your sanity," Charlie murmured, his gaze averted.

A suspicion formed in Colby's mind. "Hey, Charlie, who was that who called earlier this afternoon?"

The same rage he'd witnessed in the office that afternoon returned. Charlie gripped the edge of the counter tightly.

"An old colleague," he growled, "Asking for something I couldn't give him."

"And what's that?"

Charlie looked back at Colby, his eyes now empty and broken. "My humanity."

"I'm glad you said no, then," Colby replied.

Charlie blinked, processing the unexpected reply. He smiled. "I like you, Agent Granger. You're a good man. Can you keep a secret?"

Colby had to smile at the irony of that question. "Yeah, Charlie, I can keep a secret."

Charlie nodded. "That's true, you can. Don't tell Don."

"Uh, sure," Colby replied, not entirely sure what he wasn't supposed to be telling Don. Before he could say anything, though, another voice interrupted them.

"What's 44 times 76, Charlie?"

Charlie turned to the newcomer and opened his mouth. He closed it again. Blinking a few times, he said in wonderment, "I don't know…"

Colby gave the man a quick once over. He was tall and well-built, with dark skin, a bald head, and odd grey eyes, dressed in army fatigues. The man chuckled and said, "So the numbers are gone, then?"

Charlie grinned. "All's quiet on the western front, Derek."

Derek nodded in amusement and noticed Colby watching them. "Introduce me to your companion, Charlie?"

Charlie nodded. "Oh, right! Colby, this is Derek Myers. Derek, this is my fr-"

Charlie broke of suddenly, a lost expression on his face.

"His friend, Colby Granger," Colby finished as he shook Derek's hand.

The elation that spread across Charlie's face was a little heartbreaking to watch. Again, Colby had never given much thought to who Charlie spent his time with apart from Larry and Amita, since he always seemed so engrossed in his math. He just hoped Charlie wasn't going to use him as a replacement for Amita. In his line of work, attachments like that could be dangerous.

Derek smiled. "That's great. Come on, Charlie. You can sit on my couch and watch Planet Earth on the Discovery Channel. Lots of pictures and no numbers."

Charlie nodded again and stumbled off his seat. Derek steadied him with practiced ease.

"Easy there, Charlie. You okay?"

"Yeah, yeah, just a little tipsy," Charlie assured.

Seeing Colby's disbelieving expression, Derek called out, "Hey Mike! How much did Charlie drink?"

"He just finished his sixth," Mike shot back.

Colby and Derek sputtered.

"Sixth?"

"And he's still conscious?"

"High tolerance," Charlie replied.

"You good to walk back to my apartment?" Derek asked.

"Yes," Charlie insisted, "It's only a block away."

"Where do you live?" Charlie asked.

"Devon Apartments," Derek replied.

"Really? So do I! Which floor?"

"First, C-Wing. You?"

"Lucky. Fourth, A-Wing."

Colby set his glass down on the counter as asked Mike, "How much do I owe?"

"None, Colby. Charlie took care of it."

"Alright. You sure you can walk, Charlie?"

Charlie glared. "The next person to ask me that will get kneed in the groin."

Colby and Derek shared smirks over the smaller man's head. "Alright, big man, let's get you back."

With Charlie safely deposited on Derek's couch and watching television, Colby and Derek stood in Derek's kitchen with a can of beer in their hands.

"So how do you know Charlie?" Derek asked.

"He consults with my team at the FBI," Colby replied, "You?"

"Kid helped me out of a rough spot several years ago," Derek said, "The least I could do was let him crash on my couch once a month."

"Does he come here often? I've lived here for a year and never seen him."

"It's pretty random when he comes, but he does come once a month without fail. I'm an instructor at the Army base, so Charlie has a spare key to get in if I'm not around."

"He walks back on his own?"

Derek gave Colby an amused glance.

"He's a grown man who knows his limits. Tonight was a bad night for him. If I wasn't around, Mike would have walked him back, or, I suspect, you would have taken care of him."

Colby chuckled ruefully. "He's my boss' little brother. Don would have my head if anything happened to Charlie while I was around."

Derek chuckled, but there was a bitter note to it. "Ah, the wonders of overprotective older brothers."

"Speaking from experience?"

Derek shook his head and stared at his beer. "No, it's just… I'm probably way out of line here, but if Charlie's brother cares so much about him, why is Charlie here, and not with him?"

Colby looked away and rubbed the back of his neck sheepishly. He'd quickly learned that the relationship between Don and Charlie was a taboo subject in the office when Don was around, which was pretty much always. It was even more taboo for him, since he didn't always approve of the way Don treated Charlie.

"Ah, well, Don and Charlie have a… complicated relationship. But I promise you, Don loves his little brother more than anything."

"Love doesn't necessarily mean like," Derek returned, "But I suppose it's none of my business."

And that there was exactly why Megan and David never discussed Don and Charlie's relationship when Colby was around. Because Colby would quite adamantly say that if they cared about Charlie, it most certainly was their business.

"Are you Charlie's friend?" Colby asked abruptly. At Derek questioning look, he continued, "Because if you are, it most certainly is your business."

Derek grinned. "I like you, Granger. Good to know Charlie has others looking out for him."

Colby grinned back, but he couldn't help but feel a strange pang in his heart. Charlie did have others who looked out for him. His father, Larry, Amita… well, Amita was leaving for Harvard, but still. But, if that were true, why was Charlie drunk and watching television on a couch in a near-stranger's house?