Hello! First off, just let me say that this story is going to be epic! I'm not meaning to brag, but I've got some pretty awesome ideas for this, and I'm very excited to share them with you! I know this chapter is very short, but it was intended to be mostly a teaser, so I could see how many people would be interested in a crossover between Supernatural and Sherlock. I can't guaruntee that I'll be great at explaining all the background information, so if you're not familiar with Supernatural, you might want to skip this one. But, I can guarantee that you'll see equal amounts of Sam, Dean, and Cas and Sherlock and John. This story is going to be very dark, hence the M rating, but it will remain a friendship-only fic. But, the friendships are intense! Anyway, shoot me a message or leave a review if you think you might possibly like to read a crossover fic! Thanks a lot! :)

John Watson didn't believe in aliens. Ever since he was a child, he had known there was no such thing. His sister had tried to scare him with tales of abduction, probing, and brainwashing when he was younger, but they had never caught on. He was rational man, and always had been, so the thought of something extraterrestrial existing…no. Not possible.

Those were his thoughts up until the night that found Sherlock and him sitting in the flat, he in the chair watching telly and Sherlock typing away at his laptop madly, never looking up from the screen. At least, not until John told him to.

"Look at that!" the doctor said, pointing at the television.

Sherlock did, and his eyebrows rose in mild surprise at the picture before him. The footage showed a huge column of bright light—that was the only way to describe it, really, a column—rising up from the ground and stretching high up into the sky. Accompanying the sight was a loud, high-pitched buzzing and the strong sound of rushing wind.

Sherlock cocked his head. "What is that?"

John waved for him to be quiet as the news anchor said, "As of now, we've yet to be told what caused the phenomenon you see here. The American military claims to have in no way been involved, although they are keeping their speculations under lock and key. The two causes that immediately come to mind are terrorist activity, or perhaps something of an extraterrestrial nature. Either way, we will keep America in our thoughts, particularly those citizens of Illchester, Maryland, where this occurrence has called for a mass evacuation of the surrounding towns."

"The hell could that be?" John asked, moving around in his chair to face Sherlock. "They have to know, right? Stuff like that doesn't just happen without anybody knowing what or why."

Sherlock closed the laptop with a sigh. He knew that, now that John had seen something that was of interest to him, he wouldn't get any more work done, but instead would be forced to discuss said thing of interest for the rest of the night and, more than likely, the next morning, too. He shrugged his bony shoulders. "Of course they know. And, of course, they'll that they know."

"What do you think it was?"

Sherlock shook his head and stood up, setting the laptop computer into his now-vacant chair. "I neither know nor care."

John's eyes widened. "Well that is…surprising."

The tea kettle was whistling. Sherlock went into the kitchen and pulled two mugs from the cupboard, then filled each with the steaming liquid. He put two spoonfuls of sugar into his mug, and one spoonful of sugar and a splash of milk into John's. As he returned to the living room, he repeated John's early adjective. "Surprising?"

John nodded and took the mug from him. "Yeah. I mean, it's an unexplained phenomenon, and you don't seem the least bit interested."

"Because I'm not."

"Why not? Shouldn't you be deducing the hell out of this thing? Figuring out what, or who, caused it, and why?"

Chuckling, the detective moved his computer to the end table and sat down. He wrapped his long, pale fingers around his warm mug and stared intently at John. "I told you. I don't care. It's clearly a stunt by the American government to—"

"You don't think there's any chance it could be…"

Sherlock scoffed. "Please don't tell me you believe in that kind of thing."

John raised his hands in resignation. "No. Of course I don't. Aliens, UFOs…no, of course not!"

Raising an eyebrow, Sherlock prodded, "But…"

"But you saw it!" John practically shrieked, flinging his hand towards the television screen that was now displaying a commercial for a new flavor of digestive. "What's that thing you say? If you've eliminated the impossible, whatever remains must be the truth. Right?"

Sherlock took a small sip of tea before answering his flat-mate. "That has no bearing here. Nothing's been eliminated. John, I promise you, there is nothing supernatural at work here."

Sherlock didn't realize that across the ocean, there was something supernatural at work. In Illchester Maine, in a stone room of a church, two brothers clutched at each other as a loud buzzing filled their ears, bright white light filled their eyes, and dread filled their hearts.

Lucifer was coming.