So when a tall, skinny man who looked vaguely like a brown haired Elvis wearing a brown pinstripe suit and Converses stepped out of the Box, Britain was totally disappointed.

"Well, if it's not the TARDIS." Britain mumbled to himself, "Why is it here? These things have gone out of commission years ago. Decades. What shall I do with it?"

"Sorry?" the man in the suit asked. "Who are you, and why do you know about the TARDIS?"

"I should ask you that! Who are you?" Britain asked. "Making a cheap mock-up copy of my favorite spaceship!"

"I'm the Doctor." the man said. "And you?"

Ah.

Britain relaxed. He finally understood. The man was a new country. Obviously one from the UK, judging from the accent, and his knowledge of Doctor Who. But that made him Britain's (extra) responsibility.

"Arthur Kirkland." Britain introduced himself. "And that's obviously not your real name. And where are you situated?"

"What?"

"Like Sealand for example." Britain tried to be as clear as possible. "He's off my coast. Where are you?"

New countries were so dumb sometimes.

"I'm sorry." the man still seemed confused. "I really don't have the slightest idea of what you're talking about, but I have to go find something. Excuse me."

Britain frowned. As the man pushed open the creaky blue door to the Police Box and walked through, he slipped through the door along with him.

It was bigger on the inside.

Although it looked almost nothing like the Tom Baker TARDIS, it was a TARDIS.

Britain finally understood. It was a trick. "I get it."

The suit man whirled around from where he'd been typing on the console. "Yes?"

"This is a trick. One of my friends told you about my late night marathons, and you've made a TARDIS, and pretended to be the Doctor, even though I haven't seen you at all before. Well, happy to tell you, it is not funny. Not after all we've just been through. So please, just tell me who you are."

"I told you before, I'm the Doctor."

"No, you're not."

"How can you tell if I am or not?"

"Because the REAL Doctor wears a scarf. He has a lot more hair than you do, and a cute tin dog named K-9."

"I loved that scarf!" the man broke into a huge smile. "But how do you know about it?"

Britain frowned. The man must be a bit thick. "I watched it. I'm almost done with the Tom Baker series."

"How do you WATCH my life?"

"Your life? How far can you take this joke? I watch the episodes. On DVD. Online. They stream instantly now."

"DVD? How...? That's not possible..."

He typed faster, eyes intent upon the console screen. "Ah... I'm starting to get the picture."

"What picture?"

"Where we are. What just happened."

"What do you mean where we are? We're in London."

"Not my London, weelll, if I have a particular London, which I don't, not exactly, but it's not any of mine. Not yours, either, apparently, which means..."

The interior of the TARDIS echoed with the sound of someone knocking on the door.

"Those two men!" the Doctor's eyes lit up. "Open the door, please, Arthur Kirkland."

Britain pulled the door open slowly. Standing outside were two men. The two men he'd seen as he'd madly dashed for the box.

One was very tall, had an angular face with a mop of curly black hair. He was wearing an overcoat, a pair of gloves and a scarf.

The other was short, stocky, had closely cropped greying hair and was wearing a grey ribbed woolen sweater.

The Doctor rudely pushed Britain away from the door. "Pleasure to see you men here. I'm the Doctor. Perhaps you've heard of me? This man certainly has." he gestured to Britain. "Care to join us?"

The taller man, obviously the leader, nodded. "Yes, thanks."

When they were all standing in the TARDIS, the Doctor turned to them. "So who are you, and where are you from?"

"I'm Sherlock Holmes, and this is John Watson. We're both from London."

The Doctor's eyes lit up at the mention of their names. "Oh, brilliant. Sherlock Holmes himself. And Watson! Can I have your autographs?"

Sherlock's mouth twitched up. "You've heard of us, I suppose?"

"Who hasn't?" The Doctor dug for a pen and some paper. "Most well-known crime solving duo in history! Well, besides Nancy Drew and the Hardy Boys and the Boxcar Children, but they weren't half as brilliant as you. I mean, you were just two, brilliant blokes using their minds. How fantastic is that?"

"Right, well," Watson muttered, pointing to Sherlock. "He's the brilliant one."

The Doctor turned. "No, you both were." He sniffed. "Hang on a second though." He sniffed some more, then tasted the air. "You don't smoke!"

Sherlock raised an eyebrow. "No. Neither do you."

The Doctor waved his hand. "Well, naturally. It could kill you. But you should! You should have the felt ear cap and the pipe! You should-" He stopped, midsentence. "You shouldn't be wearing leather gloves from Abercrombie and Fitch."

Sherlock frowned. This weirdo wasn't the only one who could tell things. "Well, you shouldn't be able to be here. This box is a dimensionally transcendent pocket, probably in time as well, seeing as you haven't aged in quite a while. Telling by your slightly more than eccentric wardrobe choices and your comfort at being around something as alien as this ship- because that is what it is- you're obviously not from around here. Anywhere near here. You're an alien, Doctor."

"Oh, just brilliant." The Doctor smiled happily. "What else can you tell me about me?"

Sherlock scrutinized the Doctor closely before speaking again. "You're old, very old. But somehow this body is new. The way you move, they way you are unfamiliar with the way things work in your mind and with handling your machine skills."

The Doctor met Sherlock's eyes, dead on.

"You're in pain. I can see it in your eyes, the way you walk, like you're holding up the weight of the world. You lost someone- lots of someone's, probably. And the guilt I can see in your eyes implies you either blame yourself because there's no one else to blame, or it really was your fault."

"Okay." The look of pain was unmistakable now, as the Doctor averated his eyes and got up for the console. "You're right."

Sherlock nodded smugly. "Thought so. But why are you here?"

The Doctor smiled as he dashed around the console, typing and switching and levering. "You should probably be able to tell."

Sherlock smiled a small smile. Mysteries. He closed his eyes. He'd already figured it out.

A/N
On the subject of timelines... Doctor Who- sometime after the Utopia saga, before Donna.

Hetalia- anytime, but they know nothing of the Pict.

Sherlock- It doesn't really matter... But Watson lives on Baker Street.