"So get this," Sam says, handing the newspaper article to his brother. "Five disappearances in the last three days. Five! The victims are just gone without a trace. No kidnapper, no link between them, nothing. Just gone."

Dean looks up from his breakfast. "So what, you think this is demons? But why would they be taking random people?"

"I don't know, maybe it's demons. I think it's a case, though. We should look into it."

"Okay," Dean says. "But after breakfast."

"Dean…"

"C'mon, dude, it'll only take five minutes."

Sam surrenders and goes to pack his bags. "Should we call Castiel?"

"Yeah, we could use the big guns, if it is a bunch of demons."

"It could be the work of angels," Sam points out. "Maybe they're, I don't know, gathering an army, picking off random people."

Dean snorts. "Yeah, a five person army. Real effective against Lucifer."

"Whatever. If it is angels, Cas will know. Call him, will you?"

Dean grumbles, "Why's it always gotta be my job to the angel?" But he pulls out his phone and dials anyway.

In four hours, they meet up with Castiel in Manassa, Colorado, population 917. In a town that small, five disappearances doesn't go unnoticed. Something is definitely wrong.

They do some sleuthing. Castiel hasn't heard anything on the angel radio lately, but they're not sure it's demons either. None of the usual signs are present; the town's had no recent electrical outages or crop failures.

Eventually they find themselves in this old, rotted house on the outskirts of town. According to the townsfolk, this place used to be haunted, so no one goes near there anymore. Disappearances aren't usually a vengeful spirit's MO, but already this case is peculiar. They check it out, just in case.

Dean's almost beginning to think there's no case here when they run into the strangers. Literally.

They're turning a corner, EMF out and beeping, when bam! Two people cross their path from the opposite direction.

Normally they'd stop for introductions, but it's pretty suspicious to run into strangers in a haunted house in a town where people are disappearing, so the first thing Dean and Sam do is pull out their guns.

The woman flinches back. "Don't shoot!"

Dean keeps his gaze locked on her, waiting for the predictable flash of black in her eyes. It doesn't come. Her eyes are soft, brown, and wide with fear. "Cas?" he asks gruffly. "What are they?"

When Castiel doesn't answer, Dean turns to see why.

Castiel and the other stranger, the man, are locked in an intense staring competition. Cas doesn't blink, but apparently neither does this man. Castiel squints his eyes in concentration, and the other man mirrors him.

Sam takes the momentary distraction to reach inside his coat for a flask of holy water. In one swift jerk, he splashes it on the newcomers.

Both of them sputter and recoil, but neither of them react like demons.

"What was that for?" asks the woman.

"You human?" Dean asks.

The strangers exchange a weighted look.

"Yes," says the woman. "My name's Martha Jones. Just put down the guns, and we'll talk. We're on your side… I think."

Dean's eyes flit to the man. They're the same height, but somehow this man seems taller. "What about you? Are you human?"

"I'm not causing these disappearances, if that's what you're asking. I'm the Doctor. We're trying to stop the problem. We're looking for them too."

"Looking for whom?" Sam asks.

The Doctor stuffs his hands into his pockets and furrows his brow. "The angels, of course."

Dean's so surprised he lowers his gun. "Who the hell are you, and how do you know about them?"

"We're tracking them," says Martha. "We're trying to figure out what's going on. We only learned of their existence a few months ago."

"What are you, then?" the Doctor asks. "Human?" The question is strangely formal, like there's some underlying curiosity. He cocks his head to the side, oddly reminiscent of Castiel.

"Yeah, Sam and I are," says Dean. "And considering what you know, well, I'm sure you know what Cas is."

"You didn't introduce yourselves," reminds Martha.

"I'm Sam, and this is my brother Dean. We're hunters, like you. And this is Castiel. He's a friend." Sam holsters his gun, figuring these people aren't a threat anymore.

"Castiel." The Doctor rolls the word over his tongue. "Interesting name."

"I could say the same about yours," Castiel replies coolly.

"I'm not criticizing. Just gathering information. You said you were hunters? What, exactly, does that mean?"

"You don't- who are you people?"

"We're just passing through… America, judging by your accents. And, what's the year, late 2000s?"

The question's curious, but Sam doesn't focus on it. "Yeah, Colorado. 2009."

Martha and the Doctor exchange another look. He says, "So, obviously you know a thing or two about the angels. How did you plan on stopping them with guns?"

Dean, Sam, and Castiel exchange their own secretive look. Finally, Castiel says, "We did not know this was the work of angels. We simply came to investigate the disappearances. What evidence do you have?"

Dean understands Castiel's defensiveness. Dean would hate to have his family charged with a bunch of disappearances, even if it was the family against which he'd rebelled.

"Well, it's pretty obvious, innit?" says the Doctor. "A bunch of people disappear and then show up fifty or sixty years in the past? No other explanation."

"Sorry, what?" asks Sam.

"Come now, didn't you do your research? All the people who disappeared just went back in time. Read old newspapers, it's all there."

"Sammy? Is this true?"

Sam glances at his brother. "I don't know, Dean. I didn't look that far into the town's history."

"And you blame this on the angels." Castiel glares intently at the Doctor.

"Well, yeah," says Martha. "Do you know of any other species who can manipulate time that way?"

She's got a point. Dean likes this woman. Maybe after this case is over… Nah, she seems pretty attached to the Doctor. Still, it's not often Dean comes across an intelligent, resourceful, and beautiful hunter. Not since Jo…

No, he won't think about that. The wound is still fresh in his mind, the guilt still gnawing at him.

"Cas, if it is angels, our guns aren't going to be of much use," Sam says quietly. "Do you have-"

Castiel nods and draws his Angelsword.

Martha snorts. "Like a knife will be much good either. They're made of stone; they're impervious to bodily harm."

Dean double-takes. "What?"

"I said they're made of stone. Your knives and guns won't hurt them."

Dean barks a laugh. "Uh, last I checked, angels aren't made of stone."

"And when was the last time you came across one of these monsters?" asks the Doctor.

The brothers immediately lunge for him, eyes blazing, guns out.

"Don't you ever call Castiel a monster again," threatens Dean. He won't let that stand. Nobody treats Cas that way. Sure, some angels are dicks, but they're not monsters. And Castiel is their friend.

The Doctor's eyes widen and he stumbles backward. "Excuse me! I'm sorry; I didn't mean to offend you."

"Yeah, and insulting our best friend isn't offensive at all," Sam retorts.

Castiel places a hand on Sam's shoulder. "It's all right, Sam. He meant no harm."

"Meant no-" Dean has yet to lower his gun. "What do you mean, he meant no harm? He just called you a-"

"I'm sorry," the Doctor says, "but I don't quite entirely understand… what I said to offend. I wasn't referring to your friend here. I was talking about the angels."

Dean gears up to punch the man again. "Yeah, well, they're still his brothers, so don't you-"

"Dean," Castiel says, and the word carries weight. Dean lowers his fist. "I don't think he realizes."

"Realizes… what?" asks Martha.

Castiel fixes his stare on her. "I am an Angel of the Lord. We thought you knew."

"A what?" asks Martha.

The Doctor looks suitably surprised. "Hang on… Oh! Blimey, you're a new species! No wonder there was something off about you, I couldn't quite put my finger on it but-" He steps forward to shake Castiel's hand, but Dean pushes him back roughly.

"Hey, hands off. You did just insult the guy."

The Doctor's eyes widen. "Oh. Oh. Gentleman, I believe there's been a misunderstanding here."

"Yeah? That's your excuse? Start explaining." Sam crosses his arms.

"We thought- we were talking about the weeping angels. You know, big stone aliens? Have a penchant for sending civilians back in time and feeding off their time energy?"

Dean glares stubbornly. "Sorry, not ringing a bell."

"Nevermind that, you were talking about real angels. Oh." The Doctor grins widely. "This is brilliant! Absolutely brilliant."

"Sorry, still not following," says Dean.

"Nor am I," adds Martha.

"We were speaking of two different species entirely," explains Castiel. "They know of, and were tracking, another species called the weeping angels. We were, of course, referring to my brothers."

"Oh! And these weeping angels, they're monsters. So the Doctor really wasn't trying to offend Cas," finishes Sam, finally catching on.

Dean still looks suspicious of the strangers, but he lowers his weapon. "So these disappearances aren't being caused by angels?"

"Well, not exactly, they are, but not by your kind of angels. They're being caused by weeping angels," says the Doctor, as if that explains everything.

"And weeping angels are…?"

"Quantum-locked humanoids. Older than me, and that's saying something. They feed off of time energy. Martha and I just discovered them a few months ago, so we've been doing some investigating. We tracked their energy signature to this house."

"Quantum-locked humanoids. You're saying they're aliens." Dean scoffs. "Yeah right. Aliens aren't real."

The Doctor raises an eyebrow. "Before today, I would have said the same about angels. Speaking of which, how do you work?" He turns his attention to Castiel and pulls a silver screwdriver from his suit pocket.

"What's that?" asks Sam.

"It's a sonic screwdriver. I'm just analyzing your friend here." He looks down at the screwdriver's readings. "Oh, that's interesting. Very interesting. Martha, this is brilliant."

"What is he?" asks Martha.

The Doctor looks back up at Castiel, eyes shining. "You're a celestial being trapped in a human vessel. That's-"

"Brilliant, we get it," says Dean.

"And you live in harmony with the humans? Fascinating. I've never seen anything like you in my previous visits to Earth."

"That's because they stayed in Heaven, up until recently," Sam says, ignoring the comment about visits to Earth. He's still in denial about the whole aliens thing. "Cas rebelled."

"You're an outcast from your species," says the Doctor. "I can relate."

"Are you saying you're not human either?" asks Sam skeptically.

"Nope. I'm a Time Lord. I'm from Gallifrey, and I'm older than you. Although, for once, I'm probably not the oldest person in the room. That's new." He smiles a toothy grin at Castiel.

"Aliens." Dean can't conceal his own smile. "That is so freaking cool. Sam, aliens!"

"You're taking this rather well," says the Doctor.

"Yeah, well, when you hunt demons for a living…"

"Doctor," says Martha, tapping her companion on the shoulder, "I think we have more important things to worry about right now."

"I'm sorry?" asks the Doctor. He follows her line of sight to the end of the hallway, where… "Oh, dear."

Dean, Sam, and Castiel all spin in unison. Thirty feet away from them stand two statues of angels.

"I take it those are your 'weeping angels'?" Dean says.

"Yes. Don't take your eyes off them."

"Seriously," says Martha. "Like he said, they're quantum-locked. I don't really know what that means but basically they can't move as long as someone's looking at them."

"So, hypothetically, if we all blinked at once-"

"They move faster than you can imagine," says the Doctor. "So, hypothetically, don't. Unless you want to get zapped back in time."

Dean laughs shakily, eyes still fixated on the stone angels. "Yeah, but if that happens, my man Castiel can always work a little mojo and bring me back. Right, Cas?"

"Actually, Dean, my powers have waned considerably since our last trip back in time."

The Doctor, while still looking at the statues, is entirely focused on Castiel. "Oh, brilliant, you angels can time travel as well?"

"Yes, although it requires an enormous amount of energy. I have some, but not enough."

Dean curses. "Okay, so, don't blink."

The corner of Martha's mouth twitches, as if remembering an old joke.

"That is not a problem," says Castiel. He steps confidently in front of the others. "For me, blinking is unnecessary."

He fixes his eyes on the statues, gaze unwavering. The ultimate staring contest.

"Man, this is intense," says Dean, eyes flitting back and forth between the two species of angel.

"There is no competition," says Castiel. He disappears with a flutter of wings, and a second later he's standing directly in front of the angels.

"Castiel, be careful! If you touch them-" the Doctor starts to say.

Before he can finish, Castiel places a hand on the weeping angel's forehead. For a moment, light streams from his palm into the angel, and then it explodes into chunks of rock and dust.

He swings his arm to the other angel and disintegrates it as well.

For a moment, there's nothing but stunned silence. Then, quietly, Dean says, "Man, I love it when he does that. Angel powers kick ass."

The Doctor goes to Castiel's side. "Thank you," he says. "That was impressive. We had no way to stop them, as of yet."

"It was no difficulty. They were bottom-feeders, not very powerful."

"If only we had an angel on our shoulder for every encounter…"

Castiel fixes the Doctor with a stare. "My place is with the Winchesters."

He smiles, like he expected that answer. "I understand. We appreciate the help, though. You know, if you're not too busy, I'd love to speak with you some more. It's not every day I meet a new species, and rarely one as intriguing as yours."

Castiel turns back to where the brothers are speaking with Martha. His steely gaze grows fond. "Perhaps we can, as Dean would say, 'go for a drink.'"

"It would be my honor," says the Doctor.

Together, the angel and the alien leave the dusty old house behind.