Reasonable Doubt

Written in response to cottoncandy_bingo prompt: believe. First try writing for Numb3rs. Ugh, established relationship between Colby and Charlie (who is not dating Amita, obviously). Might try to add another part. Characters are not mine, please enjoy! Comments are awesome.

"Charlie!"

Don's sure he'll be here. Where else would his brother be? Not in his office at CalSci, certainly not at the FBI offices, so he has to be at home. "Charlie, you out here?" He calls, as he heads out to the garage, his genius brother's typical haven.

No answer comes, but he hears the crash-bang of something falling over, landing hard on the concrete floor and his training has him moving before he even makes the conscious decision to do so. Gun drawn, he nudges open the door and enters, surprised to find no one but his brother, who seems to be taking out his frustrations on the chalkboards. Some have been knocked over, their wooden frames snapped on impact, others haphazardly erased, scribbled on, the work below the harsh lines nearly indecipherable and Don recognizes the alarming sight of the dreaded P vs. NP problem mixed with something else.

"Charlie, Charlie. Whoa, there," he says, putting the gun away and reaching out for his brother, preventing the destruction of yet another board, this one covered in precisely predicted probabilities and variables with carefully assigned values, a very familiar name scrawled at the top. "What is all this?"

"What do you think?"

Don sighs, a calming hand lands on his brother's shoulder. "Look, I don't want to believe it any more than you do, but we have solid evidence. He confessed, okay?"

"You don't get it," Charlie huffs at him, pulling away.

"I... don't think I do," he admits, "As frustrating as this is, I didn't think you'd pull out the unsolvable problem for it."

Charlie seems to deflate, perching carefully on one of the many piles of boxes scattered around the garage. He puts his head in his hands and sighs the kind of world-weary sigh Don had hoped he'd never hear his brother make. He gestures to the boards that still remain, both those brandishing new P vs NP work and those tallying Colby's measured guilt. "That's just it. They're both unsolvable. Statistically, going on what I know about Colby, there's no way this can be true. I've tried so many different equations and they all..."

"He confessed, Charlie. Carter's had him compromised the whole time," Don explains, still bitter about the betrayal himself, "Maybe none of us really knew him."

Another chalkboard hits the ground, pops out of its frame. "I did," he shouts, fingers tangling in his hair. "I did, I know I did. I do. There's no way."

"Charlie," Don chides, with a heavy sigh. "I spend more time with him than you and I... I didn't see this coming, either."

"There are a lot of things you don't see, Don," Charlie counters, rather ominously, before breaking out an admission that tilts Don's world off its axis: "I was sleeping with Colby."

"What!?" Don demands, suddenly angry again (though he's not quite sure if it's directed at Charlie or Colby or the both of them, not even sure what for) because he hadn't thought this whole messed up situation could get any worse. Evidently it can, though, and it has. "You and Colby?"

"Yeah. Yeah, me and Colby."

Don struggles to catch hold of one of the thousands of thoughts spinning through his head as he processes this new and surprising information. Amongst the storm of 'I didn't know you were into guys,' and 'what about Amita?' comes the rather tactless, "How long has this been going on, Charlie? Damn it, what were you thinking, getting involved with him?"

"Maybe try criticizing my relationship when you aren't sleeping with one of your own agents, okay?" Charlie fires back at him, "You don't care that Larry's dating one of your agents, why should you care that I am?"

But that is not the same thing at all. "I don't know, Charlie - Maybe because Larry is not my brother, you are. Because Megan is not a traitor spying on us for the Chinese government, and, according to Colby himself, he is. You can't see why I might have a problem with that!? God, Charlie, all of your algorithms, he could have given any of them to his contacts. Did he... did he ever ask you to work on anything unofficial for him?"

Charlie is not amused by this rather interrogation-like line of questioning. He folds his arms over his chest and glares. "What, you think he was just using me for information? Nice, Don."

Don has no idea what he thinks right now, this is all just way too much to process. "Maybe," he blurts out, but Charlie's incredulous expression makes him explain, "I - I don't know, okay? He's with you, he asks for a favor, some work on some problems and then that's your work he's handing to the Chinese. I find it kind of weird that all of a sudden he's with you, and I've never heard him talk about anyone except girls."

"You've never heard me talk about anyone except girls," Charlie counters. "It was my idea to keep it a secret, he actually wanted to tell. I didn't think he would, between the Army and the FBI and well, you, but he did."

"Charlie..."

"He never asked for my help with anything that wasn't directly related to a case. We tried not to talk about work much at all when we actually got time together."

Don tries this from a different angle. His brother is not a criminal, not a spy, Don doesn't need to play hardball on this one. Charlie is just someone who got some seriously shocking news about someone he cared about. "Okay, good. And I'm sorry."

Charlie nods, seems to accept his apology. "Can I see him?"

"Can't do that," Don answers.

"Can't or won't?"

"I can't," he says, "he's being transported to the prison now. Solitary, no visitors, no contact."

Charlie looks like he's been punched in the gut. "Already?"

"Traitors rank pretty high on everyone's priority list, Charlie."

The chalk is moving again, flying over the blank space on a half-erased board, leaving rushed, messy scrawl in its wake. "No, no. There has to be something I can do I refuse to believe ... There's... he's not. He's not a traitor."

Don had thought he'd been doing a pretty good job of talking Charlie off of the unsolvable problem path, but it appears he'd been incorrect. "Charlie," he says again, prying the chalk out of his brother's stiff fingers.

"No!" He shouts, grabbing it back, scribbling out a mess of numbers and letters that even Don knows aren't in any kind of meaningful order. "You weren't there. After Carter got arrested, after Colby caught the guy for you, you weren't there." That was more than seven months ago, Don calculates. How long have they been together? "He was so messed up about it. Everything he told me... there's no way."

"Charlie. You're too close to this. Way too close. I get it, I do. You don't want it to be true, don't want to think he could do something like that, but he did, Charlie. He confessed. I personally delivered his taped confession to the DA before I came here, I'll let you see it, if you want. But, it's done."

For some reason, that seems to be the thing that finally gets through to Charlie. Don watches his brother sink down, until he's kneeling on the concrete and looking thoroughly devastated. "I just -"

Don sinks down, too, slides an arm around his baby brother's shoulder. "I know, I know."

Charlie's head lands on his shoulder, and Don tries to ignore how he shakes in his arms, the tears that soak into his shirt, but all he can think as he comforts his brother is that this is all Colby's fault. But that makes him pause - Colby's not cruel. If he really wanted to cause damage, then telling Don - on tape - about Charlie would have compromised all sorts of things for all of them. But, he hadn't. Colby had no reason to protect his relationship with Charlie if he weren't invested in it, and surely a spy had bigger priorities than that.

Maybe he'll take a closer look at that tape.