Summary: What's Castle's crazy theory this time? That Gotham's legendary vigilante Batman beat them to the punch. Yeah, sure. Batman (Nolan)/Castle crossover.

Prompt/Prompter: Oroburos69. This is much shorter than I intended it to be, but I hope you still enjoy it.

Disclaimer: I do not own Castle or Batman. All rights remain with owners. Written for fun, not profit.


"The Man, The Legend"

"Yes, well, that could be what happened." A well-practiced raise of one brow followed. "…Or…"

Castle let the word linger in the air, watching his prey get caught in its hushed intensity, before leaning forward, a mad scientist's delighted grin at his lips. Esposito, still feigning his study of the news clipping-plastered wall in front of him, and Ryan, his farce completely lost, both, subconsciously mimicked the writer's movements, a fully captured audience. Ryan even crossed his arms, readying himself like an eager student awaiting his mentor's wisdom.

"Or?" Ryan urged.

Kate snorted, her half-smile not so maniacal. "Castle, usually your theories come at the beginning of a case, not after it's already solved."

"Solved?"

Castle's outburst stopped a wide-eyed young officer in her tracks. The somber chatter in the house all but ceased, for a good second or two—Castle's antics were becoming well known, even to the crime scene techs. Castle was too appalled to notice, his face frozen in an open-mouthed frown, but Kate's hard stare forced his volume down a few notches.

"Not that I'm saying we have the wrong man," Castle began anew, his voice lower, "but this case wasn't 'solved' by any stretch of the imagination—"

Kate arched a brow. "…And you'd know something about stretching the imagination…"

Castle went on, unperturbed, "—Mr. Killmore, which, by the way, is a horribly obvious alias for a villain, was practically dropped in our laps with a ribbon on his head, in the form a very painful looking goose-egg. Nay, I say! This was not solved—at least, not by us. We may not be at the beginning of this case, that I granted you. We're also not at the end, but stuck in the middle, my dear Beckett."

"Castle."

"Too far with the 'my dear' part…?"

Ryan coughed down a chuckle, but whatever humor he'd found in the statement left when he glanced over to see a tech bagging a blood-stained gag. A crazed abductor's play room was enough to sour anyone's disposition.

As if deciding now would be a good time to interrupt, Ryan waved one gloved finger. "So, you're saying Killmore didn't slip up? All the evidence points to a B&E—"

Castle sighed. "Yes, a B&E where the supposed thief found more than he bargained for, struggled with our serial killer, knocked out Killmore, and decided to anonymously phone in his ghastly find. But doesn't that seem just a bit too clean to you?"

"And I haven't known many criminals who'd risk getting caught after committing a crime just to help us out," Esposito agreed.

"Not you, too." Kate shook her head, her expression an even mix of exhaustion and aggravation. Up until the tip, they'd been working non-stop on the murder of a high school sophomore who'd met her fate only a few miles from this very house. Of course, at the time, the murder was still fresh, and they'd had no clue that their criminal would turn out to be a wanted serial killer who'd just relocated to NYC. "Castle, I see what you're trying to do here. This case wasn't entertaining enough for you. The criminal had a cliché name. There weren't enough twists and turns for you to take notes on. So you're trying to complicate things. I get that, I do, but this case is closed, and the Captain agrees with me."

"Still…" Ryan said, and shut up as soon as he felt Beckett's gaze fall on him.

Castle slipped between them, putting an arm around Ryan's neck and urging the two other detectives closer. "Oh, if it were only that simple," he said, the devious smile re-plastered on his face. His tone was low, conspiratorial. "Perhaps you've forgotten one very important fact about the criminal known as Val Kilmere, AKA Mr. Killmore—he was previously a citizen of the great City of Gotham. In fact, he even took a very short vacation in the infamous Arkham Asylum before his inevitable escape."

Castle paused, straightening in preparation for his victory. Beckett shook her head. "And?"

"And…" Castle frowned, upset that his audience wasn't following his train of thought. "Okay, seriously? Have all of you been living under a rock for the past decade?" He pouted at the lack of response from the three. "Who do we know who hunts down Gotham City's craziest for fun? Hint: his favorite color is black and he has pointy ears."

Esposito raised a hand to stop him. "Wait—you're kidding, right? That vigilante that was all over the news a few years back…You think that Batman joker is in New York?"

Ryan perked up. "You think so? I thought he was just a legend made up to scare thugs."

"Nope. Not a legend," Kate said, her frown deepening. "Just a lunatic in a cape who used to play crime solver. And who happens to still be wanted for murder, in case you've forgotten, Castle."

Castle wagged a finger. "Actually, from what I read about the evidence against him—"

Kate groaned. "Nevertheless," she interrupted, "he hasn't been seen in quite a while. In Gotham or elsewhere. Castle, I'm too tired for this. It's been a long day, and I've still got a victim's mother to contact about the sicko we just caught. Not to mention paper work for this solved case."

Castle stared after her when she ducked beneath the crime tape and disappeared out the front door.

"Huh," he said. "Is it just me or was she particular unhappy that I…" His voice trailed off when he realized the other two detectives had already stepped away, talking to each other. Castle shrugged. "Well, I still think it was the work of Batman."


Kate rolled her neck, one hand bracing the nape for the ache the stretch would release. She kicked her front door shut behind her, snapping the lock into place and dropping her keys at the front table, along with her jacket. And, as much as she loved her heels, she was already fantasizing about kicking them off. But she didn't. Instead, she watched the yellow glow off the lamp, searching for movement, shadows on the light. She didn't see any, but she didn't trust her eyes.

She felt it, then, the slight chill in the air. There wasn't a doubt in her mind; the window in the other room was open.

"You're not supposed to be here," she announced.

He stepped out from behind the separation wall, but he didn't move into the center of the light, hanging back, in the darkness of the main room beyond. Moonlight stretched across, outlining his black uniform with white. His footfall should have been deliberate, loud, in all that armor, but it wasn't. Kate wasn't sure what his secret to stealth was, and she didn't plan on asking. Trade secrets and all.

"I came for Killmore."

The voice was forced, gravel being ground into cement by a thick boot, and completely unnecessary. Kate didn't bring it up, though. "You got him," she said, instead, balancing her hands on her hips. "Killmore's going away for good. And not to Arkham this time. So what are you still doing here?"

Kate watched him for a tell. He gave none. "I know you're still seeking answers to the same questions." His weight shifted, ever so slightly, but he didn't move forward. "I can help you."

She watched him a moment longer, before answering, "I don't take help from vigilantes." Kate licked the salt off her top lip, willing her voice not to break. "Not anymore. I think it's about time you headed back to Gotham."

He didn't nod, but Kate knew, instinctively, that the suggestion would be heeded. Batman's eyes stayed on her a moment longer. "Kate," he said, a little less rasp to his voice, "was that Rick Castle with you at the crime scene? The writer?"

"The legend, himself."

Kate couldn't be sure, but she thought the split-second sound coming from the Bat was a laugh. She smiled back, but the expression was more than a little bitter. "You'd like him. I think you'd have a few things in common."

Kate turned away, ready to pour herself a drink. The move was calculated, slow, and she knew it would give him enough time to slip away. For some reason, Kate didn't think she'd be seeing him again, at least not in this city. The Batman's work was done.