Disclaimer: All things "Castle" belong to Andrew Marlowe & Co.

Author's Note: Written because I love Ryan and it occurred to me in re-watching "Probable Cause" that, aside from Beckett, he would be the quickest one to believe in Castle's innocence. Thank you, as always, for reading and reviewing.

Beyond a Reasonable Doubt

Kevin Ryan pushed open the door to his apartment with a sigh.

"Kev?" he heard Jenny's voice say and then he saw her, her smile immediately changing to concern. "What's wrong?"

He sighed again and threw himself down on the couch, rubbing a hand down his face before he answered her. "We arrested Castle."

She gasped and then sat down next to him. "But why?"

He turned to look at her shocked face, reaching out automatically to brush a strand of hair away from her face—and for the first time, such a gesture, touching her, didn't make him feel anything. He just felt… numb… too exhausted by the day to even feel at all comforted by her touch or her nearness.

"This vic," he finally began slowly, trying to organize it in his thoughts, wondering if summarizing the evidence again to Jenny would make it somehow real to him, make it make sense. "The scene was wiped clean of prints but CSU found Castle's prints on the door knob and around the door and they took them before Castle and Beckett got to the scene. So he must have been there."

"But that—" she began.

"I know. That wasn't enough. We found... more. Searched his place and found a bag with bloody clothes and the wire that was used to tie the vic up. Surveillance video of Castle buying earrings for the vic. And emails. He'd deleted them from his computer but Tech retrieved them and…"

And he trailed off. This was really where all this got unbelievable. More unbelievable. None of this made any sense! It was evidence—damning evidence—and evidence speaks, as they said… But none of this made any sense.

"Emails," he began again, heavily. "Between Castle and the vic showing they'd… been having a relationship." He paused and met Jenny's eyes. "And here's the thing, Jenny. Castle and Beckett are—they've been seeing each other. They finally got together… and now this…" He stopped, let out a little breath, and then said, in an oddly flat tone of incredulity and anger, "he's been cheating on Beckett."

He's been cheating on Beckett. Cheating on her…

The words seemed to echo in the room, in his mind. And maybe it was a sign of just how exhausted, his brain barely functioning, he was that for the moment, Castle's cheating on Beckett seemed worse than the murder of the victim to him. He saw again the look on Beckett's face when he and Javi told her about the emails. "I just… I can't believe he would… how could he do that to her? I know he has a reputation as this rich, famous playboy but he's not—he hasn't been that guy in the last couple years. He… I know—we all know—how he feels about Beckett. I just can't see how he could—" He broke off and turned to Jenny in sudden, irrational urgency. "Jenny, I know we've joked about the 'Freebie Five' and all that but you know I wouldn't—even if any of the Five were—I'd never—"

She cut him off, touching her fingers to his lips. "I know, Kevin," she said simply. "I trust you. I know you wouldn't cheat just as I know you could never kill anyone in cold blood."

In cold blood. No, he couldn't. He was a cop; he could kill people to defend himself or others but in cold blood—no, he couldn't.

Could Castle?

He was too much of a Homicide detective to say categorically that someone just wasn't capable of killing but this kind of killing?

"What does Rick say?" Jenny asked quietly.

"He says… it's not true. That he's never met the vic. That all of this has been… faked… somehow…"

The flat denials, even the confusion. They heard it, saw it, every day. Even when they had damning evidence. Just like they had here. Were they really to believe that, because Castle was one of their own, he alone was telling the truth in his denials?

He dropped his head back against the couch, closing his eyes. "I don't know, Jenny."

"How's Kate doing? God, I can't even imagine how she's handling all this…"

He winced, seeing for maybe the hundredth time the look on Beckett's face when he and Javi told her. Beckett was never easy to read but the look in her eyes… He'd felt as if he'd killed something she loved right in front of her.

Something she loved—like her relationship with Castle.

Funny, in all these years and in the weeks since he'd found out about her and Castle, he'd never thought of the word, love, in the same sentence with Beckett—and now, when it might all be over, for good—he found himself thinking, Beckett loves Castle.

Beckett didn't trust easily and she certainly didn't love easily, but she'd let her guard down with Castle, let him in, given him her trust and her love—and now… God, what would this do to Beckett? Beckett was the best cop Ryan had ever met, including Captain Montgomery, and possibly the strongest person Ryan had ever met on top of that. But this… if it turned out to be true, he didn't know, just didn't see how even Beckett could recover from this.

"I told her… as she was leaving, I told her it wasn't what it looked like." He'd actually just said, "Beckett, this… may not be what it looks like." He didn't even know if he'd believed it at the moment; the words had just come because he couldn't stand to see her looking the way she did. As if she'd just taken a bullet to the chest. He inwardly flinched at the metaphor.

"What does she think?"

"I don't… know. God, Jenny, I just don't know. I couldn't… she looked so… stricken… but I don't know if she believes… I don't know what I believe right now."

"Kevin." Jenny's voice was gentle. "Look at me."

He did, turning his head to meet her eyes.

"Do you think Castle did this?" she asked directly, though her voice was quiet.

Her eyes held his, soft and trusting eyes he loved, eyes he could not lie to—and somehow, looking at her, he knew the answer. "No."

She rested her head against his shoulder. "See, Kev, you do know what you believe. You believe in your friend."

"But I can't!" he burst out in some frustration. "It's just—there's no reason to believe in Castle's innocence and every reason not to!"

"No, there's one reason to believe in his innocence. He's your friend." Her voice was still soft but it was also firm.

The words stopped him cold. "It doesn't work like that, Jenny," he began, not even sure why he was arguing. She was right and he did think Castle was innocent because Castle was his friend—but he couldn't stop himself from arguing. He let out a sound that was almost an unamused bark of a laugh. "Beyond a reasonable doubt—that's the phrase lawyers use. Beyond a reasonable doubt," he repeated. "Reasonable doubt—not just whatever we might invent or imagine or speculate about—a reasonable doubt." He'd been in court; he'd heard what judges said, how they described reasonable doubt to juries. "If Castle goes to trial on the evidence we have now… this is so much beyond a reasonable doubt, it's not even a question." Oh, sure, all cops heard of cases where there was more than probable cause to arrest but a lingering doubt—that bit of uncertainty—about whether the guy had actually done it. And all cops heard of cases where they were convinced the guy was guilty only to have the jury find the guy not guilty. But this—Ryan didn't think there was a jury in the country that wouldn't find Castle to be guilty. "Me believing in Castle's innocence because he's my friend—Jenny, that's not a reasonable doubt." He paused. "I do think he's innocent. But it's not based on evidence; there is no evidence that helps him, there's no reason to doubt—it's just… my gut, really." His lips twisted into a bitter sort-of smile. "It's an unreasonable doubt."

Beyond a reasonable doubt.

What was reasonable about doubting all the evidence?

He was a detective; evidence was everything. Only—it wasn't, was it? Ryan could practically hear Castle's voice in his head, asking—as he did so often—what's the story that makes it all make sense?

What was the story—mystery novelist plotting the perfect murder and then committing the perfect murder? That was a story—but it wasn't the story, not the one that made it all make sense. Maybe in some murders it might have been, could have been, so simple. Evidence speaking.

But not this murder.

Castle wrote about murder all the time, even spent his time planning murders on the page… The planning on paper of the perfect murder was something he could easily—maybe even too easily—imagine Castle writing—it was the carrying out of the plan, the doing of it, he couldn't imagine Castle doing.

The bare fact of Tessa's murder wasn't so disturbing. He dealt with murder, the usual, garden-variety murder, every day. Crimes of passion, crimes of opportunity, crimes of revenge. Those he could generally deal with. Not easily, but he could. This—this wasn't that. This was… evil. This was psychopathy. It was the coldness of it, the plotting, the careful staging, the meticulous details right down to the relationship with the vic, and then coolly, deliberately, following the plan. In cold blood. This was the work of someone who enjoyed murder.

And that was it, he thought, with sudden clarity.

Castle wrote about murder, yes, but he didn't enjoy it.

Ryan suddenly remembered the times Castle talked about Beckett's mother's murder. He thought of the look he'd occasionally caught on Castle's face in talking to the victims' families, in watching Beckett talk to the victim's families. That man, the man he knew, could not have done this.

"Castle didn't do this," he found himself saying aloud, not as if he needed to convince himself but as if he was stating a truth as obvious and undisputed as saying the sun rose in the east. And for the first time that night—no, the first time that day—he felt calm. Reassured, somehow, just to have his certainty back.

"See, Kev, you do know what you believe," Jenny said again, gently.

He actually managed a small smile at her, drawing her closer to kiss her forehead. "I don't believe Castle is innocent. I know he's innocent."

"Then I guess you'd better find evidence to prove it," Jenny said simply. "And you will."

He looked at her. "You really think I can prove him innocent in spite of all the evidence?"

"If he's innocent, there'll be evidence to prove it and you'll find it. I know you will."

He stared at her, a little amazed all over again at her steadfast confidence in him. And even though part of him knew it was irrational, that sometimes it just didn't work that way that someone's innocence could be proven, at that moment, he believed it too. And not for the first time, he thought that this was why he needed her.

Once, years ago, his training officer had told him that in this job, where it seemed like every day they encountered the worst of humanity, it was advisable to have something that was apart from it all, a safe place, a haven. Something that would restore your faith in humanity so you wouldn't turn into one of those cops, the cynical ones, the bitter ones, the ones who thought everyone in the world was guilty and there were no innocents left to protect.

He didn't know how he'd gotten so lucky but, looking at Jenny now, he knew, yet again, that she was his safe place, his haven.

He drew her close and kissed her and then settled her head against his shoulder, putting his arm around her and resting his cheek against her hair. And felt himself relax, the tension and the stresses of the day leaving him. After the day he'd had, a day that had shaken his faith in one of his closest friends, one of his partners, a day that had made him question almost everything he knew about how to be a cop… In spite of all that, now, because of her, he was calm.

Castle was innocent. And somehow, he, Javi, and Beckett would prove it—beyond a reasonable doubt.

~The End~

A/N 2: It was really hard to write Ryan and Jenny together just because of how little we see of her and them together; I hope my portrayal of them doesn't seem at odds with what we've seen.