Sherlock is in the kitchen, sitting up on the counter beside the fridge, with a bottle of excellent wine and a glass.

Jarvis told him who was coming. It's the second-last glass, which hasn't seemed to matter much, but which gives him an excuse not to care. If he wants to sit on the kitchen counter at half five in the morning failing despite his every effort to get drunk, he'll do it, and damned if he's going to run and hide when she comes down the stairs.