Author's Note: I blame my roommate for this.
Sherlock Holmes unlocked the front door of 221B Baker Street and confidently walked up the stairs to his flat. He had it all worked out – exactly how he would make his entrance, precisely what he would say when he explained the whole elaborate plot he had concocted. Oh, how surprised John would be! How he would admire the cunning it took to outwit everyone! John, at least, would be able to appreciate how hard it had been to say that he was a fraud, that none of his brilliant deductions had been real at all.
Hesitating on the fifth stair, Sherlock reminded himself that John was one of those people who held his emotions in great importance. He'd seen how torn up John had been – even crying at his empty grave. He'd looked devastated to lose his best friend, and surely the months that had elapsed since then had been hard on the man. Were John here to advise him how to proceed (though that was illogical, since John could hardly advise him how to approach himself in a way most sensitive to his feelings), he would probably tell him to restrain everything that made Sherlock who he was. He would have to try to be boring and ordinary, just this once.
Sherlock nodded to himself. It was worth the effort, if he could save John a little pain.
With a flourish, Sherlock threw the door open and announced cheerfully, "Guess what, John? I'm not-"
He stopped in shock, then stared in horror. The entire room was crawling with cats. Cats of all sizes, shapes, and colors. Cats dozing on the windowsill, cats clawing the sofa – his sofa! – to shreds, cats walking daintily along the mantelpiece and sending skull, knife, and preserved insects clattering to the floor. A particularly fat one, curled up contentedly on his Union Jack cushion, looked at him and gave a loud meow.
John turned towards him, seated in his armchair and petting another cat in his lap. A black kitten nosed at his cup of tea experimentally. "Sherlock!" John exclaimed in mild surprise – much milder than Sherlock had been expecting.
"What...What is this?" Sherlock gasped, pointing wildly around the room. "Where did all these cats come from?!"
John looked rather sheepish as he scratched the cat under its chin. "Well...it was raining, you see, and...it just looked so cold and hungry... So I brought it home, but...then it had kittens, and... Well, you were dead, and I had to have someone to keep me company."
Sherlock clapped a hand to his forehead and sank onto the sofa in a cloud of felines. "The great detective Sherlock Holmes has been replaced by cats!"