Sherlock sees them, the nameless dead. They’re not so bad, they fade into the background. They are long dead, and nothing can be done now. Time has ensured that, they have accepted that.
It’s the others he sees that are bad, the ones that have died today or yesterday, recently, who still hope for some kind of closure.
Most can’t tell him, can’t talk. They’re beyond that and no one is taught sign language on the off-chance that they’re murdered. He can do his best with their faded images, they can give nods, shake their heads or point to some clue he may have missed. But usually it’s the material world that provides the answers.
It has to, anyway. What jury would believe the evidence of a ghost?
They’re desperate, they plague him. Their pleading looks are his incentive, their melancholy, despising presence guilt him into sleepless nights, their unheard moans put him off his food. In the land of the living, only Mycroft and one other realise he can’t sleep, can’t eat, can’t stop, not until an answer is found.
Sometimes he just wants a break.
The worst are the ones he can’t help. The murders where no one will ever know the culprit, where the evidence, supernatural or not, is too slim for even Sherlock’s well trained eye. The accidents that the ghosts cannot accept, the evils that cannot be punished. All he can do is try and ignore them, try to keep himself sane.
Lestrade helps. He knows, somehow, although they’ve never talked about it. There again, there’s something different about Lestrade, Sherlock thinks. So he knows, and he knows when it’s all getting too much. Something in his attitude shifts slightly, an unspoken ‘leave him alone,’ which never works with the living but never fails to make the dead back off for a few precious hours. That’s why Sherlock’s alive, not another barely remarked upon suicide.
He likes to listen to Lestrade’s heartbeat, Lestrade’s fingers gently combing through his hair, to remind himself that there are still the living who need him. Or rest his hand gently on Lestrade’s pulse, feeling the warmth and movement under his fingers. Or watch him breath. That’s enough. That gets him through.
He debates whether to tell John, what to tell him. In the end, he tells him nothing. He never needs to, fate has kept 221 ghost free, excepting the newly-dead trailing after him. John never observes the obvious, the way Sherlock looks intently at someone invisible to most, the small clues that seem to come from mid-air, the way Sherlock is hounded throughout his cases.
And so he works for those who have lived and those who still live. And so he lives. And one day, like all others, he will die.
His will be a peaceful death. He’s done enough to ensure that, at least.