John. John steadies him, holds him together. John, with his firm, gentle hands and strong chest. John.
John would pull him from a barricade when all around the world is falling apart. (The world was falling apart - masks pulled off in a whirl of gunshots and shadows. And he was so sure that this time he'd gone too far, this time he really hadn't been careful enough, and John was there steadying him. Holding his hand and murmuring softly words which Sherlock can't remember anymore but that doesn't matter. It was enough that it was John.) Even if he had to carry him through a sewer, John would find a way to save him.
And Jean is John too. How could he forget that? Jean is John and John is Jean and it doesn't much matter because Jean (no, it's John) will always be there to help him right himself. It's what he does best, after all. John keeps him right.
John, for his part, is surprised when Sherlock watches Les Misérables without complaint. Then again there is little else to be found on the television and with his dose of the flu Sherlock isn't in much of a position to complain. Now, his head is heavy in John's lap, breathing steadied out albeit still groggy. Thankfully his fever is well down now. One less thing to worry about.
It's not that long, John chuckles, since Sherlock laughed at Mycroft having to take their parents to a matinée of "Les Mis" (in his own words) while he managed to avoid it. Then it's probably different watching a film version in the comfort of 221b without his parents in attendance.
He presses a kiss to the back of Sherlock's hand and sighs. If someone had asked him years ago if he ever thought he'd be watching a musical with Sherlock Holmes he'd have laughed in their face. Now just look how far they've come.