Sherlock departs from the morgue of Barts, cigarette still in hand. He knows that Mycroft is already informing John of his decision to accept the cigarette, and he scoffs at how deeply his brother seems to read into his actions. Honestly, he took the cigarette because he wouldn't be able to get any from anywhere else. John had made sure of that. That was all, he keeps telling himself.
He takes another drag as he makes his way towards the exit, but realises he's nowhere near finished with the cigarette, and if he wanted to get into a taxi, he'd have to put it out and waste a perfectly good source of nicotine. So he turns around, taking a detour so he can find a place to finish his cigarette in peace, heading back up a flight of stairs instead of down, and finds himself on the roof in no time, feet crunching through the untouched snow as he makes his way over to the ledge. He dusts off some snow and sits down, facing away from the vertical drop, bringing the cigarette to his lips once more so he could take a long drag from it.
When he exhales, the vapours are two-toned - the heavy grey of the burning tar and the white of the steam of his own breath in the cold midnight air, mingling together, creating swirling images composed of light and shadow. For a moment, he can see her in the smoke, hiding, laughing at him. He stares up at the ephemeral image until it dissipates into the atmosphere, lost, just like her.
He shakes his head. If anyone were to see him right now, they would laugh at him - the great Sherlock Holmes, all wrapped up in sentiment over a woman he had only seen once and known for less than three months. Because he is feeling a bit sentimental right now - the only person he had ever met that could match him, even beat him, is gone. To him, she was The Woman. Not just in the professional sense, but she was the only woman, in Sherlock's eyes. She was representative of her whole race, even predominated it. And there could never be more than one of her, of someone like her, so clever and sharp and powerful. Sherlock is sure that if there were ever two Irene Adlers, the world would explode. He chuckles at the thought of two Irenes - one was quite a handful, two would be impossible to handle. But he would accept the challenge anyway.
His temporary amusement fades and he is left with an ache in his chest again, the same ache that developed when he had unwrapped the present from the mantle piece and found her camera phone. It's psychosomatic of course - he doesn't have any heart or lung problems and he is perfectly healthy, by his own standards anyway. But that doesn't stop the pang of...of something in his chest every time he remembers that The Woman was no more. This must be what other people call grief, he thinks to himself, grimacing at the feeling. No wonder those people downstairs by the morgue were bawling like newborns. The pain in their chest combined with the emotional stress of losing a loved one would be enough to make anyone regress to the mental state of a four year old. Sherlock knows Mycroft was right when he said that caring is not an advantage. Sherlock is proof of that - he didn't care overly about her and now, in the hour of her death, he is calm and composed and clear-headed. But there is something else that keeps bugging him, that is eating away at the back of his mind. What if he had...cared? What if he had cared enough about her, could he have ensured her safety? Would she still be alive if Sherlock had used the heart he supposedly didn't have. The thought makes the pain flare and he scrubs at his eyes as the nonexistent wind blows some smoke into them, making them tear up. He should have...he should have done something to protect her. Then he wouldn't be in this position. Maybe Mycroft was wrong. If caring meant she would still be alive, then it definitely was an advantage, wasn't it? Sherlock sighs. Even he isn't sure any more.
All the while, he has been smoking his first cigarette in months, dragging the chemical fumes deep into his lungs and expelling them out into the night sky, feeling the nicotine calm his jittering nerves much more effectively than any patch or gum. Resting his wrist on his knee, he flicks the butt of the cigarette, watching the ash fall and the bright orange cinders fade away and die as they lose their spark and are snuffed out. All lives end. Just like Mycroft said. Sherlock stands up and drops the butt to the ground, extinguishing the remaining embers as he steps on it and makes his way back downstairs. All lives do end, he thinks to himself as he gets into a cab to take him back to Baker Street. I just wish hers didn't have to.