A few hours into darkness and John Watson found himself stepping out of a cab on a deserted street, rows of old warehouses rising around him. He followed after Sherlock, who wasted no time in finding their target building, and couldn't help noticing the foreboding ambience of the place, obviously abandoned for some time. There was no sign of the police just yet, though the building was mostly boarded up and featured its fair share of NO TRESPASSING signs.

"Lestrade told us to wait for him," John attempted halfheartedly. Sherlock didn't bother to answer, though John thought he heard a mocking mutter under his breath as he unlocked the door. "Pickpocket his key, then?"

"Of course I did," Sherlock said as the door swung open. "He can't tell me the address of some violent murder and expect me to wait around for him and his paperwork."

John nodded. But of course.

The warehouse had obviously not been used in several years, but still it was lit with a series of dim bulbs hanging from the ceiling and walls at odd intervals. Low, amber light illuminated the grisly scene before them. It appeared to be a woman, facedown and sprawled out on the blood stained concrete, her clothing torn away from her. A chair was upturned beside her, torn ropes dangling from it as though she had been tied to it at some point. Tape and chalk outlined the scene; seeing as how no one else knew about it yet, John assumed it was a weak attempt to ward off Sherlock's presence.

Sherlock turned and surveyed the space, beginning his examination. John waited patiently, ready to listen to his conclusions, but an echoing voice interrupted the ritual.

"Hey! What do you think you're doing here?"

Two men in dark suits strode towards them, apparently having entered the warehouse from the other side. The man in front looked ready for a row; his tall companion looked calmer, at least, though he had more hair than any man had any right to have.

"Sorry, who are you?" John asked.

"Agent Robert Plant," the shorter man flashed his ID, the taller following suit. "This is my partner, Agent Jimmy Page."

John blinked at them, but Sherlock cut in. "I'm Sherlock Holmes. This is my blogger, John Watson."

"Your blogger?" Agent Plant scoffed.

John shrugged apologetically. "We solve crimes. I blog about it." Sherlock shoved past the other men and stepped over the police boundaries. "He disregards the law in general."

"Yeah, well, you have a problem there," Plant said, tugging away his page, watching as Sherlock bent over the body. "'Fraid we're gonna have to ask you guys to leave."

"We'll begin with what Americans are doing here in the first place," Sherlock spoke as he worked over the body. "On a local case that's only just been discovered."

"International serial killer," Page explained. "We've been following him for some time."

"Oh, really?" Sherlock stood and looked up at the agent. John only then realized just how tall he was. "What's his name?"

"None of your business," Plant snapped. Page swept his hair out of the way and switched on a flashlight, grimacing at the body. "Now, both of you get out."

Sherlock turned to Plant. John could almost smell his brain firing.

"We're not going anywhere," he said. "And I'll tell you why. You and your partner here are not agents and you are not after any kind of serial killer. You're amateurs, hobbyists. You take a fascination in this kind of thing-can't say I blame you, to be honest-but you're out of your depth. Obviously this trick has worked before, judging from your confidence. So you make this a regular part of your routine, impersonating agents. Vague title, too. Handy for you, as I'm sure people rarely ask for any more than that.

"American, obviously, and recently flown in, judging by the creases in your clothes and the bags under your eyes. You, especially, Agent Plant," Sherlock smiled his cold smile. "Not a fan of flying, are we?" Page grinned and Plant shot him a glare. "But you must've been here for awhile. Long enough for a date-that is lipstick on your neck there, isn't it, Plant? Just a dab, hardly noticeable, especially in this light. Ah, Page is surprised. So you were separated after your arrival. What for? Investigating?

"It's quite clear you are neither Plant nor Page, not agents, not partners. You hold yourselves in similar fashion-obviously you've spent a great deal of time together; I'd even say most of your lives. Far too much time if you were simply partners, in any sense of the word. You could be childhood friends but your habits and ticks are too similar. Siblings, then."

Plant grinned, teeth gritted. "Wow, you are really something. But you can't really prove any of it, can you?"

Sherlock smirked and looked to the other agent. "I can, actually. Those badges would not possibly stand up in any court, but that's hardly necessary. Agent Page, you are aware your ID is signed Han Solo, I'm sure."

The two intruders looked at each other, 'Page' fishing out his ID and looking at it again before treating his partner to a venomous look. "No, I was not."

'Plant' shrugged. "Dad always said you should check your equipment yourself."

"Ah, so you are brothers," Sherlock continued, apparently having lost interest in the rotting corpse at his feet. "Deceased father. Advice on your job. Continuing the family business?"

"Look, asshat-" Plant started forward, but his brother grabbed his arm and held him back.

A car door slammed outside, followed by a man's cursing. Obviously Lestrade discovering the opened door and his missing key. The brothers' eyes darted towards the door, but Sherlock's gaze was unwavering. "I highly suggest you leave. The London PD and I have a professional if shaky relationship. I imagine things will be much more complicated for you."

"Fine," Plant grinned sardonically, shook off his brother. "We'll go. C'mon, Sam."

Page-now Sam-watched his brother stomp away and exit through a door towards the back, then turned to Sherlock and John. The front was down; he was no longer a hard, serious agent hunting an international serial killer. His face was kind, worried.

"Look," he said. "You guys don't know what you're getting into here. Back off. Let us deal with it."

"Please," Sherlock-Sherlock I-Can-Do-No-Wrong Holmes-scoffed. "I can handle a murder."

Seeing he wasn't going to get anywhere with Sherlock, Sam looked to John. "Just be careful, okay?"

"Yeah, sure," John said, brow creasing. "But what-"

"Sherlock!" Lestrade's voice boomed and echoed in the warehouse. John's head jolted around to face him, and when he looked back, Sam was gone. Sherlock was hunched over the body once again, and Lestrade marched towards them with an oversized flashlight. "I told you to wait."

"Fascinating," Sherlock muttered.

Lestrade craned his neck for a better view. "What?"

"Oh, nothing, just you thinking I'll do as you say," Sherlock stood up with a smile. "As for the body, well, that's just plain strange. You don't have any lights in here?"

Lestrade shook his head. "Just the one. Got a crew on the way. Why, what did you do with yours?"

"Ours?" John asked.

"Yeah, when I came in, there was a light on," Lestrade glanced between them.

"Job must be getting to you," Sherlock said with a quick glance at John. "Seeing things."

"The only thing's getting to me is you," Lestrade snapped. "Now tell me about this. What's that on her neck there?"

"Oh it's exactly what you think it is," Sherlock said.

John stepped around them so he could see. "Bite marks?"

"Outstanding, John," Sherlock said, kneeling beside the corpse again, tilting her head for a better view of the bloody, jagged ring on her neck. "But it's unlike any bite I've seen. I'll have to look into it." He stood and faced Lestrade. "You said the place was locked up when you arrived?"

"Right. Two boys-teenagers, screwing off-found the body when they entered through a hole in the roof," Lestrade reported, shining the light in the direction of said entrance. "Building's locked from the outside."

Sherlock was silent, thinking. Then, be abruptly turned and strode towards the door.

"Well where are you going?" Lestrade called after him.

"To think, I need to think," Sherlock replied, John hustling out the door after him.

"Frickin' idiots are going to get themselves killed," Dean growled, muttering about backwards foreigners as he sped the rental car down an empty street.

"You're the one who signed my badge Han Solo," Sam said. "And using names of British band members probably didn't help."

"Oh, whatever. That freak of nature-what was his name? Surely? Sherry?"

"Sherlock."

"Right. Sherlock. Christ. How the hell did he know all that just by looking at us?" Dean shook his head. "Dunno. Something about the guy's off. Hell, maybe he's the monster."

"Maybe," Sam didn't sound anywhere near convinced.

"Demons. Demons can read minds. That's how he knew," Dean shook his head. "And before you ask, yeah, I stopped on the way here and-Jesus shit!" He swerved to avoid being hit by a cab, then drove over into the left lane. "Learn to drive, jackass! Why are we even here?"

"We followed a vampire here, genius."

"Yeah, but why are we still here?" Dean complained. "We ganked the vampire on the plane; we could've turned right around and gone home."

"Yeah, 'cause you're gonna get right back on a plane after an eight hour flight," Sam chuckled. "Just chill out. That other hunter asked us to look into things while we're here, so we're looking into things. Whatever it is, we'll gank it and head home."

"Yeah, whatever it is. What do we think it is?"

"You see the bite on the neck? Could be another vampire. We'll have to get back in there."

"And that's gonna be a piece of cake with mind-reader Sheldon hanging around."

"Sherlock."

"Whatever! You mark my words, Sammy," Dean grumbled. "One of those idiots is going to end up dead before this is over."