A/N This is my first fic so please let me know what you think. This prologue is rather short, but there's more to come if you like it!
Amy Pond gasped and spun around to face the Doctor. "Wait a minute – Baker Street? You're telling me that we're outside 221B Baker Street? No... No way, you've got to be... no!"
A grin lit up the Doctor's face. "Yes indeed, Pond, the home of the famous Sherlock Holmes himself! And his companion as well, of course. Another Doctor. I think he fancied me a bit. Fancied Holmes a bit. Well, more than a bit..." He trailed off. Stepping around Amy, he swung the door open and squinted at the warm sunlight hitting his face. "Well, what are you waiting for? No time for dilly-dallying, Pond. Come along!"
Amy let out a squeal before remembering: "Rory! Hurry up or we're leaving without you!"
A head popped out from behind the TARDIS console. "Yes, coming. Uh, just a minute."
"What are you wearing, Rory?"
"Well, it's a jumper, if you must know. For keeping warm. Because it's cold out there."
"And you want to seem fashionable. It isn't working, you know. But no time now – come on!" She grinned and took his hand.
The Doctor was already ringing the bell as they shut the blue doors behind them. "Ahhh, I can't wait to see my old friend Sherlock. It's not often I pop in just to say hello, you know. Last time I did that I... Well, you know. Anyway, I think you'll like him. Wears a deerstalker. Deerstalkers are – " He froze. The door to the apartment had opened, and standing in front of them was a very small, very fragile looking woman. "Err.. yes, well... " Visibly flustered, he smiled briefly before looking at Amy and Rory. Oops, he mouthed. He held up one finger – wait a second – and turned to face the woman. "Uh, yes, hello there. Can you just give us a minute?" Without waiting for a reply, he ushered the Ponds back toward the sidewalk.
Amy was livid. "Doctor! What's going on? Doctor..."
"It's okay, Amy, I'm sure the Doctor has a perfectly rational explanation for whatever that was." Rory looked at him. "Right Doctor?"
"Oh, yes, yes of course. We seem to have arrived a bit too early in Sherlock's timestream. He, er, won't quite know me just yet. Nothing a little jump into the future can't fix. If I just recalibrate the density fibrillators I can probably jumpstart the locker ke – "
"No!" said Amy, rather forcibly. "You said it yourself that it's hard enough getting the right century. Plus, you told me five minutes and you know where that got us! No, I just want to meet Sherlock Holmes, have a cup of tea, and then we'll be on our way. Come on, Rory." She grabbed his arm and marched toward the door, where the woman still stood with her hands on her hips.
The Doctor watched them for a moment before begrudgingly following along. "This isn't right," he muttered. "This is very not right. If that's who I think it is, and I think it is, then this could be very bad. Very, very, very not good..."