John trudged heavily down the stairs for the last time.
Sherlock listened to his lopsided gait; his limp had been steadily deteriorating over the past several weeks, as it became apparent that this – whatever “this” is – was not working. The added awkward weight of the suitcase he was carrying didn't help, either.
And there he is, standing at the foot of the stairs, shoulders hunched, face looking ten years older than it had any right to, eyes pained, yet something else lingered there. Hope. Oh John. John was hoping that the sight of him – sad, hurt, leaving – would spur Sherlock to action, change his mind, awaken the long suppressed emotions that John believes are hiding somewhere deep inside Sherlock's psyche. Please, John's eyes plead with him. Ask me to stay.
Sherlock will do no such thing. Because John is wrong. Because John still does not believe, even after everything that's happened, in Sherlock's sociopathic nature. He still thinks that Sherlock is capable of feeling love, if only he would let himself, if only he would try.
But Sherlock has tried. John doesn't know how hard Sherlock has tried to love him back. John doesn't know how badly Sherlock wanted John to be right, to wake up one morning or lock eyes with John across the kitchen table and feel what John felt (feels) for him. John doesn't know how disappointed Sherlock was every time those feelings failed to make an appearance.
Not much cop, this caring lark.
Sherlock's own words, and how he wishes he had taken them to heart. Because he does care about John. John is his best friend, the only person who never abandoned Sherlock, who never called him a freak or looked at him with suspicion or disgust. John never made Sherlock feel like anything less than extraordinary. John had loved him, still loved him, would still stay if Sherlock asked him to, even after everything.
And Sherlock wants him to stay. He wants to say the words, Don't go. Don't leave me here alone. But he doesn't, because he sees the pain in John's eyes, knows that he put it there, and knows that the sooner John leaves, the sooner that pain will go away. At least he hopes it will.
So Sherlock says nothing, just looks at John coldly from the sofa, and John gasps shakily, as if he is choking back a sob (he is), and says quietly, “Well...” He doesn't know what else to say.
Sherlock just continues to watch him, to drink in the sight of his best friend, his only friend, who is about to walk out of his life forever. Sherlock knows he did this, that he is to blame for this loss. He knew better, he knew from the start that it was no good, that he could never love John the way John loved him. But he tried anyway, and now it's all ruined, it is all not fine , and there's no going back now, no way to fix this. So Sherlock simply stares at John, doesn't ask him to stay, because he knows if John stays, he will only continue to hurt, and contrary to what John may think of him now, Sherlock doesn't want him to hurt, doesn't want to be the cause of his pain. Sherlock does care.
But even that can be remedied. Sherlock's (7%) solution to that little problem is in the velvet-lined case currently residing under the couch. Sherlock hasn't made use of that case in over four years, and right now he just wishes John would leave, because he is positively itching to pull out that case and take the plunge. It is waiting for him, has been prepared for this moment ever since John went upstairs to pack the last of his things. Sherlock wants to get on with it, already. To feel that glorious emptiness, that beautiful oblivion that washes away all the noise and colors and just leaves him blissfully blank.
Sherlock watches as John's face changes, becomes hard, indecipherable. John stands up a little straighter, and Sherlock is fascinated by this display, this soldiering on that he has seen John do before, but never to him. John gives a little nod, tells him, “Goodbye, then.” And turns toward the door.
Now John is walking to the door. Now John's hand is on the door knob. Now John is turning the knob, opening the door, walking across the threshold. Just as he's about to close the door behind him, he stops. Stands frozen solid, a moment in time that is everything, that means everything, that Sherlock will remember forever. A moment that will haunt Sherlock, causing him to chase the needle that will wipe all memory away, if only for a few short hours. Sherlock watches him, holding his breath, wondering what he will do. John does not turn to look at Sherlock, he merely stands there, frozen for several (four) seconds, then, without turning around, he whispers, barely audible, “I love you.” He shuts the door. He is gone.
Sherlock releases the breath he didn't know he was holding. He reaches under the couch for the case. A single tear escapes his eye to trail down his cheek, one tear for the one friend he had, the one friend he will ever have, the friend he ruined, broke, chased away with his stupid, selfish experiment.
But all that will go away in a matter of moments. Sherlock ties off his arm, takes the prepared syringe out of its case, and admires the way the light glints off its surface. He finds a vein, and chokes back a sob at the feeling of the cool steel pressed against his flesh. Sherlock smiles as he plunges the needle into his arm.