It was cold, windy, damp. So different to the last time he'd been on this rooftop, gazing down at the street below. Standing on the ledge, about to jump, Jim Moriarty's corpse with its head in a pool of blood and brains cooling on the asphalt behind him. He gazed down at the street from his perch on the very same ledge, this time his only goal the exorcising of personal demons that continued to plague him. The fear of heights was temporary, restricted only to certain London rooftops, including this one, but he needed to rid himself of the ridiculous phobia before it grew and eventually crippled him.

He took a deep breath, opened his tightly shut eyes, and finally allowed himself to look down. Down to the site of his fall. The place where John Watson had rushed to his side, staring at him in shock and disbelief. The place where he'd "died."

A moment's dizziness overtook him, but he shook it off. Resolutely continued to stare down at the pavement far beneath his feet. Took a deep, steadying breath. Stepped back off the ledge and onto the roof proper. Demon faced, phobia hopefully vanquished, he remained for a moment, eyes closed, simply breathing in the familiar scents of the London air, a miasma of trash and traffic and cooking and...blood?

His eyes snapped open and he looked around for the source of that familiar tang. There should be no lingering smell of blood on the rooftop, not after two full years. Not after rains and the clean-up crews and certainly not after new asphalt shingles had been laid only three weeks ago. So where...

Well, I can't say I'm surprised to see you up here, Sherlock. It was only a matter of time, wasn't it?

He stiffened at the sound of that voice, familiar, hated...belonging to a dead man.

A truly dead man, not one who'd merely played dead like himself. Jim Moriarty had killed himself, put a gun to his head and pulled the trigger, and there was no coming back from the kind of damage Sherlock had seen. As if that wasn't enough evidence, his body had been recovered by Mycroft's men and his identity confirmed. James Moriarty was well and truly dead.

So why was Sherlock hearing his voice now?

His first thought was that it was some kind of trickery; a hidden microphone, a voice impersonator, or (less likely but not impossible given the reason for his presence on the rooftop) even an audible hallucination brought on by the ambiance of this place, a place it had taken him two months to face down since his return. The lingering scent of blood would be explained by such an internal phenomenon as well, laced as it now was with the acrid tang of gunpowder.

It had to be his own mind playing tricks on him. He'd come to this rooftop to lay the ghost of his final confrontation with Jim Moriarty to rest, and thus had conjured up more visceral memories of that day as well.

Ooh, I do love watching your mind at work, Sherlock. Such a well-oiled machine, so busy dismissing the impossible in favor of...what, exactly? What am I, Sherlock? How are you hearing me?

With a jolt he realized that the voice was coming from within his own mind, was nothing his ears were actually hearing. His voice. Moriarty. Even conjured from his memory and imagination, he knew he would never have put those words in the dead man's mouth. Which meant…

No. He shook his head, trying to rid himself of the impossibility that had presented itself to him in the form of a theory. Ridiculous. Insanity. He must be losing his mind, that well-oiled machine he was justifiably proud of. Else he wouldn't even be considering...

Considering what, Sherlock? The possibility of some form of life after death? Of the existence of spirits, ghosts, demons and angels as more than abstract concepts? Daddy's impressed! I would have thought you'd fight the idea a bit harder, Mr. Pragmatic.

The voice, a mere whisper at first, was gaining in volume and power until it sounded as clearly in his mind as the voice of a living man would in his ear. Moriarty's voice and no other, right down to the light Irish lilt, the rising and falling inflection, the faint tone of mockery in every word.

He scanned the rooftop again almost desperately. There was no one else. He was alone.

He'd told no one but Molly of his intention to return here today, and only moments before making the move from statement to action. No time for anyone to set up some kind of elaborate hoax, unless such a plot had already been put in place…no. Ridiculous waste of time and effort for either a prank or an attempt to discommode him. Especially since Moran had been taken down, the last cog in the vast machinery that had once been Moriarty's criminal empire.

Shaking his head again, he started toward the stairwell, unwilling to give any possible observer a chance to either see how unsettled he really was by the odd occurrences he'd just experienced, or possibly take a bead on him with a sniper rifle. Of course, if that was the goal he'd already made a target of himself; the fact that he was still alive indicated the need to discard such a theory.

No, it was certainly his own mind that was playing tricks on him. Perhaps it had been a mistake to come back to the roof, to confront the site of his fall from grace. Clearly that desire had awakened some form of guilt or regret from deep within him, although until this very moment he would have scoffed at the very idea. Jim Moriarty had been an evil, depraved murderer who'd got exactly what he'd deserved: a lonely death at his own hands.

My, aren't we judgmental today, the mocking voice sounded in his mind. He shook his head as if to dislodge it, only to hear it devolve into a high-pitched giggle of amusement. Oh, Sherlock, you're not getting rid of me that easily. No, I'm in here now and I'm not leaving. In fact, I think it's time you went away for a bit and let me take control, hmm?

Sherlock's rapid steps faltered and halted as he felt some unseen force seize control of him. He stumbled to one knee, steadying himself automatically as his hand slapped onto the filthy asphalt shingles, his mind locked in a type of battle he'd never fought before. He squeezed his eyes tightly shut, overcome by a dizziness so profound it seemed he could actually feel the revolving of the world around him, tilting beneath his hands and knees as he scrambled for control of his thoughts…and lost.

In that moment found himself falling, over and over, tumbling through his own mind to vanish into some dark, inaccessible hole, his identity forced away from the living world.

When his eyes opened, it was no longer Sherlock Holmes looking out through them. They flashed and glowed silver for the briefest of moments: Jim Moriarty had taken possession, and the gleeful grin that split his features had very little of sanity about it.