Sam and Dean Winchester sat on a plane heading overseas to a seemingly insignificant street in London, England. Halfway through a decent nap, there was a distinct flutter of wings that woke Dean and startled Sam.

The angel with the coal-colored hair and the icy gaze sat in the end seat beside Sam.

"Hello, Sam. Dean."

Dean jumped. "Seriously, Cas?" Dean growled at the seraph.

"What did I do?"

"I was asleep!"

"Shh," Sam hissed, not wanting to alert the flight attendant to the man who had just appeared beside them. Both men quieted down.

"I have received urgent news about this light source you've been tracking. Lately, there have been reports of intense memory loss and signs of people disappearing with no trace." The angel sighed. "Even I can't track them."

Dean's eyebrows furrowed. "Is it Crowley?"

"I've detected no signs of demonic activity in the surrounding London area. Crowley must be working hard to cover his tracks."

Sam nodded slowly. "So, what you're saying is,"

"Whatever is doing this... I've never seen anything like it. This is completely new."

Dean shook his head and sighed, "We'll figure it out. Anyway, I've found a place close to the heart of the source. I got it for cheap from this lady... It's at Baker Street, apartment number 221C."

At that time, the flight attendant appeared beside the three. Sam tensed, hoping the woman wouldn't say anything about Castiel. She gave him a long look, thinking.

"Sir, we need you to put on your lap belt, we're going to be descending soon."

Sam breathed out, but Dean tensed this time. "Mmm, great," The older Winchester braced himself against the window and shut his eyes until they were on the ground again.

...

Once grounded, the Winchesters took a cab to 221C, and Castiel left in a flutter of wings to find out more about the mysterious source.

Sam and Dean carried their bags to the door of 221 Baker Street and knocked loudly. There were footsteps, and a small old lady answered the door.

"Oh hello," she beamed. "You must be the new clients, come in, come in." She was sweet and friendly. Sam smiled.
"Now, don't worry about wiping your shoes, just follow me. And don't mind the smell, it's been festering for weeks." The woman sighed. "No amount of air freshener covers it. I'm thinking it's the detergent."

She unlocked the door to their apartment. "If you'll be needing anything, I'll be in the flat down the hall. I'm Mrs. Hudson, by the way. Enjoy your stay, boys!" She walked off, leaving the keys in Dean's hand.

The boys made quick work of making a salt barrier and demon-proofing the apartment.

"Let's get to work, Sammy," Dean said, removing his FBI badge from his coat pocket.

Sam pulled out his FBI badge and straightened his tie. The brothers proceeded up the stairs and knocked on the door of 221B Baker Street.

A short, blond man in a knitted beige sweater answered the door, holding a cup of tea. He looked startled at first, then smiled.

"Afternoon,"

"Good afternoon. I'm Agent Padalecki and this is my partner, Agent Ackles." Sam greeted.

"John Watson. How can I help you?"

"We're from the FBI and we just have a few questions for you," Dean said, returning the smile and showing his badge.

"FBI?" The man's eyebrows furrowed. "If anyone talks to us, it's Scotland Yard. Did Lestrade send you?"

"No sir," Dean answered. "We're here in different business."

Another man showed up at the door in a blue robe. He was about Dean's height, and he looked them over.

"John, what's going on?"

"I don't know, Sherlock. The FBI showed up."

The other man looked curiously at them, then ushered them in. "Why would the Americans get involved with me? I'm a consulting detective, but honestly...,"

"Consulting Detective?" Dean repeated, "so you're already investigating?"

"Of course I'm investigating!"

"The strange lights?"

The man called Sherlock laughed. "Americans are sending amateurs to investigate lightning, how cute. No. If you must know, I'm investigating the murder of a woman down the street. Now if you'll care to stop boring me..."

"Wait, we just have a few routine questions...," Sam quickly said before he could be ushered out. "That's not lightning-- that's not lightning and we need your help!"

"Why?"

"Because--!"

"Because I already know all I need to know about you. You're clearly out of town but planning to stay around for a whole to investigate the thing the media is calling power surges. No one in their right mind would rent flat 221C. Judging by your hair and--"

He leaned over and sniffed Dean on the shoulder. He made a face. "--scent, you've been traveling abroad within the past 24 hours and haven't slept lately. You usually get by on usually 4 hours of sleep, though, so it's really not a problem. Judging by the accents, you're from the Midwest. I'd say Texas, but not quite there, mm, not exactly Missouri, so Kansas it is...

"You two claim to be partners, but there's clearly something more than that. Lovers? It wouldn't be a long shot in this era...," He ignored Dean's face of disgust.

"Sherlock!" John said sternly.

"...but no, the looks you share, the facial resemblance, clearly you two are brothers.

"Now why would the FBI in America send two brothers to investigate lightning when Scotland Yard knows full well that I can handle things? Well, whatever this is must be affecting Americans too. Oh, and before you say anything, yes, it's not lightning. Obviously."

He paced around the boys, gesturing to them absently. He clicked on his phone for a moment, speech never slowing.

"But I digress. Why would America send it's FBI agents? Easy. Too easy. You two don't work for the FBI at all, do you, Sam and Dean Winchester?"

Sam and Dean gaped for a moment as Sherlock passed them his mobile phone, displaying the articles about them --robbing a bank, dying, everything-- and tried to make a recovery.

"Come on. You come to a Consulting Detective and expect not to be recognized? Now tell me, Demon Hunters, what do you know and what do you need to know about the light source that's taking people's memory? Make it quick and don't be boring."