"Is this fake?" Anderson hefts the skull from Sherlock's mantle.

"No, it was a human. Now it's a skull. That's how skulls work." Sherlock waves dismissively, watching a new raid.

"Human? I knew one day you'd end up killing someone."

"He was a friend-"

"Even better. Watch out John, I think he considers you a friend," Anderson sneers.

"Then perhaps one day my skull will be there instead." John picks up his tea cup and takes a sip. He runs a finger down the mouse pad, following the medical journal he's reading.

"You're both mad."

John and Sherlock laugh together.