Disclaimer: I don't own Doctor Who or the Avengers. Just in case there was any confusion on the meaning of fan fiction.

"You're certain that he's an alien?" Natasha was on the radio with Fury as she followed a man in a long brown coat through the still under construction streets of New York. He seemed a little shocked, but mostly looked grieved and somewhat angry. He definitely looked human, but so did the Asgardians.

"We already have custody of his ship," Fury said. "Just bring him in."

Natasha nodded. "On it."

He noticed that he was being followed almost immediately. He couldn't tell who or how many were there, but he knew there was someone. He had missed this particular invasion and felt bad about it. It had been serious. But there were other people involved, he gathered from the posters and graffiti; a group called the Avengers.

Something hit him in the back and he felt woozy. He looked around, then pulled the dart out. He licked it, but nothing was coming to him. He stumbled in the crowd and ended up down a mostly empty alleyway. A woman dropped down from a fire escape and leveled a gun at him. He had enough sense left to know that this wasn't a mugging and held up his hands in peace. That was the last ting he remembered before dropping to the ground, unconscious.

Fury stared through the glass wall of the holding cell at the man with the suit. He stirred, drugs wearing off. "Where are you from?" the director asked.

"Uh..." The man sat up from the bed, finding himself strapped in with a few monitors attached.

"Let's start with something simpler," Fury said. "Who are you?"

"I'm the Doctor," he said. "Who are you? Human, I assume from the needless violence and unethical pursuit of curiosity."

Fury nodded. "You?"

"Not human, as I'm sure you've figured out. Not inclined to say anything more specific til I know why you attacked me," the Doctor said crossly, like he was scolding a child.

"Better safe than sorry."

The Doctor frowned. "That always ends well."

"Who are you?" Fury asked again.

"I told you, I'm the Doctor," he said. "Big secret organization like this and you haven't heard of me? Thought most of you had a special watchlist for me by now."

"Not usually our job," Fury said. "What's your name?"

"Just the Doctor," he sighed. It was an old routine.

"What do you want with earth?" Fury asked.

The Doctor made an odd, exasperated sound. "I just popped in for a visit."

Fury grunted. "We'll see about that." He strode out of the room.

In SHIELD's lab, they started tinkering with some of the gadgets they'd pulled out of the Doctors pockets. There was a wallet-like object that held only a blank sheet of paper, which didn't have any real purpose they could determine; a pair of red and blue 3-D glasses, which also seemed rather pointless; and a device a bit larger than a pen than buzzed with a blue light. They thought it might be a weapon of some kind, but they couldn't figure out exactly what it did.

Fury picked up the pen and took a cab over to Stark tower.

"You know, I thought I'd be getting a little break from you people after I saved the world." Tony didn't look up at Fury as entered his garage. He was busy tinkering with a car. "I'm busy. What do you want?"

"Potential alien threat," Fury said.

"How potential?" Tony glanced up slightly. "Like, demigods running around with stolen technology and you're calling us in late sort of potential or we're paranoid so we're going to bother Stark sort of potential?"

Fury was not amused. He produced the pen-like device for Tony to see. "We pulled that off an alien who 'popped in for a visit'. Our scientists are having trouble determining its function and how to use it."

"Yes, well, your scientists are morons," Tony mumbled. He set down the tools, stepped around the car and took the device from Fury. "Luring me out with shiny toys is so unfair." He looked over the device, then pointed it at a pile of unused parts and pushed its one button. Nothing really seemed to happen, but Tony found the sound interesting. He pointed it at Fury and pushed the button.

"Hey!" Fury shoved it away. "Be careful."

Tony shrugged. "It's not a weapon." He turned away from Fury and started messing with the sonic device some more. He seemed to notice something, then Fury took it back. "Hey." Tony pouted at him.

"I'm taking it back to SHIELD," Fury said, turning to leave. "You can come with me or you can stay here and fix cars that aren't broken."

"Uh, that one is broken," Tony said. "I had to rebuild the entire body after an accident from testing the first suit."

"Whatever you say." Fury was going up the stairs now.

Tony sighed. "Jarvis, let Pepper know that I'll be back later barring any alien invasions." He trotted after Fury. "So who's the guy who owns it?"

Fury smirked and the two went over to SHIELD facilities.