She arrives on the scene suitably panicked, scouring the sidewalk for any sign of a flash of metal. It would have seemed strange to them, her insistence to be the one to perform the autopsy against their protests that they could find someone else, if it weren't for the same reason they offered the protests to begin with: her regard for Sherlock had been one of the least-kept secrets in London. The real difficulty is in keeping John out of the room, but she doesn't have to lie, she only has to tell the truth.
"Please, John," she says. "It's the one thing I can do for him."
The army doctor must be even more shaken up than she had imagined he would be, because she doesn't need to come up with a second protest.
She checks the victim's pocket on a nervous impulse and finds no key. There really hadn't been a need for her to check. The man on the table is several inches shorter than Sherlock, and his hair is straight—she'll have to curl it, and she's glad again for her obsession with the consulting detective because otherwise she might not have thought to bring her curling tongs.
Calm and clinical, she artfully disguises the face and head as she works to obscure both their features and any trace of the obviously fatal bullet wound. She remembers all the times she watched Sherlock lay into corpses and has the fleeting thought that he'd be proud of her efforts. Pleased, at any rate.
It is late and the halls are dim when she completes her report. She has submitted so many death certificates, she's lost count, but she's never written one up on a friend before. "Impact trauma in consequence of fall from great height," she types as the cause of death, and her hand shakes as she signs her name.
She brings a copy home to her flat, and her breath comes ragged and shuddering as the tension of the last twenty-four hours breaks over her. Her eyes are bloodshot and her nose swollen, and she has never been a pretty crier, but then he would never have been fooled anyway. Besides, for once she isn't worried that he might observe something she didn't even want him to see.
"It's done, then," he says solemnly, turning the page over and over in his long fingers.
She doesn't tell him she feels like she has killed him herself.
For once, he seems to know without having to be told.