John barely even had to glance at the wall when he entered their small flat in 221B to know what Sherlock was staring at, the puzzle he was trying to solve. All he needed to see was the detective standing in his typical thinking-pose, chin leaned to the tip of his fingers, his body still as a statue, and his face caught in a frozen moment of intense thought. Upon the wall hung countless of photos, drawings, diary entries, newspaper clippings, printed screenshots from websites and blogs, and whatever else related to this new obsession. John thought his friend''s new case ridiculous, of course, it was all just an urban myth thought up by some Internet weirdo, probably another one of those 'scary spaghetti' stories or whatever they were called. But to Sherlock, it was perfectly real, and that's why his entire favourite shooting wall was completely covered with all of these clues, every single one leading back to the same object: an old, blue police box.
The first time John had asked about it, Sherlock had explained that back in the 50s, these blue, wooden boxes had been placed around street corners all over Britain. If a citizen witnessed a crime, they could pull the small hatch and phone the police, and if the police caught a criminal but had no way of quickly getting them to the nearest station, they could lock the person inside the box until transport arrived. And ever since Sherlock had found these silly little stories floating around the Internet almost three months ago, he'd been completely obsessed with figuring out how this box could appear all throughout history, dating as far back as the stone age. All over their wall, where actual clues for real cases were usually put up, there now hung pictures and drawings and mentions of this police box, collected all throughout history, and all obviously fake if you asked John.
"Are you still trying to solve this silly box mystery? You do know it's just-"
"No," he interrupted with the tone of a man who had had this discussion dozens of times, "No, it is not just another Internet rumour, John. If it was, I would be able to find its source. And these pictures, these drawings, I've triple checked them. They're not fakes, they're perfectly real, and most of them are very old."
"What do you mean, 'most of them'? If you're looking at a box that appears throughout history, shouldn't all of them be old?"
"No, John..." he mumbled disappointedly with an added little sigh for effect, "Some are new pictures of old things, like the cave drawings. Others are pictures or blog entries of the box appearing in our generation. 'All of history' doesn't just mean the past, it means the present and the future. And believe me, it will keep appearing in the future. Sadly I can only see the past and present, though, so that's what I'll have to stick with."
"But you can't really believe that some old box from the 50s can be in all of these places before it even existed? Or after it'd been decommissioned?"
"Actually, the one I'm after is most likely from the early 60s..." he mumbled, deep in thought again, and now barely listening to his friend.
John was just about to continue the argument when a loud, horrid noise interrupted his thoughts, but Sherlock was too deep into his own thoughts to pay it any mind. The noise was almost as if someone was playing an instrument in a way it was never meant to be played. John crossed the small distance between the door to the stairs and the window facing the street to find out what was making all of the noise, but just as he got to the window, the noise stopped. He pulled the curtains apart anyway, and what he saw made him pause in shock for a solid minute.
"Sherlock..." he said, still stunned by what he was looking at, "About that box..."
"John, for god's sake, can you give it a rest already? I don't care what you think of the police box, all that matters to me in this matter is that I know it exists, and all I want to do in this matter is to figure out how it exists, so can you please be quiet and let me think."
"JOHN, FOR ONCE IN YOUR LIFE, COLD YOU JUST LISTEN TO ME AND SHUT - UP!!!"
"YOUR PRECIOUS BOX IS STANDING ACROSS THE STREET AT THIS VERY MOMENT, YOU STUBBORN PIECE OF-"
Before he could finish that thought though, Sherlock had practically flown across the room, grabbed his coat, and sprinted down the stairs, with an incredibly frustrated John following soon after.
As Sherlock threw the front do open with a loud bang, his face lit up in an exctatic smile for the briefest of moments in satisfaction of finally seeing the mysterious box he'd been chasing with his own eyes. He was so caught up in the moment that he almost didn't notice the man leaning against the box with a smug grin upon his lips, locking eyes with the detective as Sherlock studied everything he could see about the man.
"Hello, Mr Holmes. I heard you've been looking for my box." said the man with the tone of someone who thought them self incredibly impressive, "I'm the Doctor."
Sherlock looked into the man's eyes again with a confident smirk once he'd made his deductions after studying him, and John joined his side at that very moment, looking confused as always.
"What do you mean 'the Doctor'?" John asked, and the strange man's smile grew even wider in anticipation for the next question, "Doctor who?"