Halloween probably wasn't the best night to come back from the dead.
Sherlock knew this, somewhere in the depths of his being where the child who had dressed up as a pirate year upon year still lurked. But he was so close to Baker Street – just a few blocks from his former flat, and he knew exactly what John Watson would be doing: sitting with Mrs. Hudson in her front room, probably watching some black-and-white film from the forties while they waited for the trick-or-treaters to arrive. Unless things had changed drastically in the six months, twenty-seven days and sixteen hours since the last time he had seen the good doctor, John would be sneaking candy from the bowl himself whenever he thought Mrs. Hudson wasn't looking.
Sherlock smirked. Unbeknownst to John, Mrs. Hudson would be doing the same.
He sat on the bench in Paddington Street Garden, and ducked his head deeper into the hood of his heavy sweatshirt. He hadn't been this close to his old flat since the day he...left. Died.
Lied.
Sentiment. He shook it off the way a horse shakes off a fly. But even as he did so mentally, his body stood up and moved toward the gate of the park.
This is absurd, he scolded himself. You cannot afford to make such a move at this point in the game.
That didn't stop his feet from taking the well-remembered sidewalks toward 221b. In fact, if anything, he sped up.
Tropes from old horror movies rattled through his brain like sick jokes—Frankenstein's monster, "It's aliiiiive!" Jekyll's "I'm one of the living dead!" Or even Van Helsing's "Gentlemen, we are dealing with the undead." Sherlock Holmes, terror of the criminal underworld, was a walking dead man.
Rather ironic, no matter how you sliced it.
He stood outside 221b, leaning against the railing of the house opposite, and crossed his arms over his chest. The upstairs windows were glowing softly—John must have left a light burning somewhere.
The curtain twitched.
Sherlock froze in dismay as John's hand slipped between the curtains and parted them slightly, allowing a sliver of his face to show. Who knew why he had chosen that particular moment to look out the window, or why he wasn't downstairs with Mrs. Hudson like he ought to be—Sherlock's face was clearly illuminated by the orange streetlight. And John saw him.
Sherlock, unable to move fast enough, saw John's eyes widen, and the doctor whirled from the window. He was coming down—Sherlock had to get out, and fast.
Seven seconds later, when the front door of 221b slammed open, the street was deserted. John half-ran, half-fell down the front steps and stood, coatless and shivering, in the lurid glow of the streetlight, his head darting from side to side.
"Sherlock?"
Sherlock, hidden with his back to a brick wall in the alley not thirty feet from John, held his breath. He didn't move, melding with the shadows—those puddles of darkness, the hiding places that were his only friends these days—until he heard John grumble something about stupidity, limp back up the stairs, and slowly click the door shut behind him.
Let John think he'd only seen a ghost.
Halloween was not a good night to come back from the dead.