Knight Magic (слэш)

When John and Sherlock are attacked on a London street late at night by strangers wielding mysterious weapons, Sherlock hovers over John's fallen form and calls for help. He certainly doesn't expect a three-decker purple bus to appear and whisk them away to what can only be a secret experimental medical facility. Hallucination and reality butt heads as Sherlock grapples to understand a world he has deleted, and learns that John Watson is even more than he seems, but still all that he's wanted.