A/N: Hey guys, I know I disappeared for a while, a year actually, but I'm back with a story I started a while ago. Hopefully I'll be motivated to finish it. Enjoy!
"So what you're trying to tell me is that a demon from our world teamed up with an alien from one of your planets or something and now they're trying to kill us both?" Dean Winchester looked incredulously at the shabbily dressed man who had introduced himself as only 'The Doctor'. The Doctor scratched the back of his head. "Exactly. The thing is, I have no idea what they're planning next. Normally species are fairly predictable, but this kind of alliance…only an equally unpredictable genius could figure out their next move." He fingered his sonic screwdriver. "Well, me and Sam aren't geniuses. At least, Sam isn't," teased Dean. "So how do we play into all this?" The Doctor grinned. "You're hunters, aren't you? We have a demon problem on our hands. I trust you'll know how to deal with that." He turned and walked towards the police box, a big blue thing parked at the end of the lot. "Wait!" said Dean, catching up to him. "How about I go with you and Sam can stay here and watch my baby?" He gestured to the black 1967 impala parked nearby. Sam frowned. An unreadable expression came over the Doctor's face. "You want to go on an interdimensional journey without Sam?" he said. Dean opened his mouth to protest, but the Doctor was quicker. He scanned Dean with his sonic screwdriver, looking triumphant as it beeped. "Just as I suspected. You're a zygon." Dean smiled, his human skin receding to reveal the red body of an alien. Sam stared in shock. The Doctor aimed the screwdriver at zygon Dean. "Tell me what you're planning, or I'll blast you." The alien smiled grimly. "You'll find out soon enough, Doctor. All you need to know for now is that we've got the real Dean, and he's going to die in 48 earth hours." With these words, the zygon disappeared into a demon portal, which immediately vanished. Sam blinked. The Doctor looked at him sympathetically. "I know it's a lot to take in all at once, but—" "We have to save Dean. That's all that matters," interrupted Sam. The Doctor nodded. "Right. I know a bloke. Allonsy!" "Allon what?" asked Sam. "Allonsy. It's French. Means 'Let's go!'." The Doctor disappeared into the TARDIS. "An alien who speaks French and is armed with a beeping laser pointer. Why not," said Sam to himself, before following the Doctor into the blue police box. No matter what, all he knew was that he had to get Dean back.
The real Dean was shocked into consciousness by a knife in his arm. "What the hell?!"he grunted. He realized he was in a dimly lit, stone walled room, tied to a chair, and an alien was putting some of his blood into a bowl. Shit. Blood collection never ended well for him. "So what are you planning on doing with my blood? Drinking it? Everything else has been done before," he said to the alien. "It is no concern of yours," said the creature, and left the room, leaving the bowl of blood on a small table. "It usually ends up being my concern," said Dean to himself. He glanced around the room, trying to form an escape plan. The room had no visible windows, and only one door. Broken furniture and old books were strewn haphazardly on the floor. Medieval weapons cluttered the walls. A thick coat of grime covered the floor and the cobwebs in the corners. "Nice dungeon you've got here," said Dean aloud. He tested his restraints. No chance of escaping them, for they were expertly and tightly tied. Sam was probably trying to find him already, but if he didn't hurry, well, the alien and its cronies could do all kinds of nasty stuff. A dark figure opened the door, interrupting his thoughts. "Dean Winchester. I've heard plenty about you,"it said in a deep, smooth voice with a faintly Scottish accent. "Then you must know that I'm fabulous and that you're in big trouble, pal," smirked Dean. The figure snorted. "You're the one in trouble, Winchester." Dean shifted in his seat, trying to see who his adversary was. "Hey, play fair. You can see me, and you know who I am. Come forward and introduce yourself, you bastard." The figure stepped forward. He was tall, dressed in a black and red three piece suit. He wore his dark hair to the nape of his neck. His face was pinched, his mouth curved into a permanent sneer. His bright eyes were red, and Dean got the feeling the figure was truly observing everything in sight. A black wooden cane was held loosely in his hands. "I am Enthaziel, harbinger of Doom," said the figure. Dean looked at him quizzically. "Isn't that last part already taken?" Enthaziel sighed. "I know it's generic, but all the good titles are taken. And trust me, you'd take Harbinger of Doom the Third over Harbinger of Indigestion any day." Dean cringed. "That bad, huh? No wonder you look like you have a stick up your ass." The third Harbinger of Doom gripped his cane tighter, smiling a strained smile. "I see you haven't lost your talent for pissing us demons off. I think it's about time we taught you how to keep your mouth shut. As a favor, of course, before my allies and I kill you." Dean nodded sarcastically. "Of course. It's only polite. Remind me again, when am I supposed to die?" Enthaziel held up two fingers. "You die in two earth days, hunter scum. I'll finally get the recognition I deserve when word gets out that I, not Crowley, finally killed the Winchesters." Dean looked the demon in the eyes defiantly. "Not likely. In two days, you and your cronies will be just another enemy defeated, another demon killed by us. We're professionals, remember?"Enthaziel shrugged. "You forget, you do not know where Sam is. But I do." Dean clenched his fists. "If you hurt Sam I'll kill you slowly, you son of a bitch." The demon smirked. "Your confidence is admirable. We'll see if you're still so sure in two days." He turned to leave, then changed his mind. "Oh, and if you think your pathetic little hunter brother could find our location, you're sadly mistaken. You should be honored, Dean. You're the prisoner of the first ever demon-alien alliance. And we aren't going to let anyone get in our way." He walked out of the room, locking the door behind him. "In that case, I hope Sammy finds some help," thought Dean.
Elsewhere, the Doctor was landing the TARDIS on a quiet residential road. Sam looked at him. "Where are we?" The Doctor flipped a switch, speaking over the vworp of the TARDIS engine. "London. We're going to need some help finding your brother, so I'm picking up a bloke I know." Sam nodded. The TARDIS shuddered. "Blast" said the Doctor, banging the console. "What is it?" asked Sam. "The time circuit is a little damaged. This isn't the exact year I wanted, but we're on the clock. Let's just hope his husband doesn't kick me out again." "Again?" The Doctor adjusted his glasses. "Well, yes. Last time I got invited to help on a case I came to the correct conclusion before he did so John had to escort me out before I hurt his big ego any more." "Ok," said Sam, confused. "Right, now I don't know how he'll react to you, so why don't you do some research. The library is down the hall to your left," said the Doctor. Sam raised his eyebrows. "You have a library in here?" The Doctor shrugged. "Yeah. Comes in handy." Shaking his head, Sam left in search of the library. The Doctor adjusted his suit, opened the TARDIS door, and approached the door of 221B Baker Street, hoping the genius inside would choose to help.