Afterwards, John helps Sherlock up the stairs to their own flat, Mrs Hudson going ahead to be sure that the black-out curtains are drawn. Sherlock isn't much help to the operation - being half-conscious with pain still gnawing at his leg - but they get there in the end. John puts him to bed straightaway, gently divesting him of his clothes. The trousers are only fit to be burned, but it's better to burn them than leave Sherlock a pile of dust. (How easily it could have happened doesn't bear thinking about.)
Mrs Hudson - on the other hand - makes straight for the kitchen, now containing only half of the experiments that it had earlier in the night. With a ridiculous amount of familiarity - though she is not their house-keeper - she takes several bags of blood out of the fridge for heating. Tomorrow, she will berate her boys for being so careless while they were out, but better to let them rest tonight, so she takes the blood into the bedroom (the things she's stumbled across in there remain between her and, well, not God, exactly.)
They prop Sherlock up between them, his eyes closed though he is still somewhat aware, and with the tenderness of a mother and a lover, they force him to drink the blood.