Sherlock watched him struggle with an interest in his injure but no real emotional investment or care for the fact that he was in pain. Caring that the doctor was hurting wasn't going to help him. Giving him a shot would, and since that was where they were going Holmes felt that he was doing all he could do already.
"I had to make sure people realised that I wasn't a private detective, I couldn't stand working those kinds of cases." He wrinkled his nose as he took the stairs with Gregory. "Infidelity, really, that's what almost all of them boil down too. No, I spend my time helping the police catch serial killers. They're much more fun.
At the top of the stairs he made a quick left and open the door to his flat. The second he did, the dog on the floor lifted his head with an uneasy groan, looked at Sherlock, and then dropped it down again. It seemed, Holmes noted, that Watson wasn't here.
As for the room itself, it resembled a chemical laboratory (the kind belonging to a mad scientist, not one in a sterile, clean, hospital environment) much closer than it did a man's flat. There were bottles and tubes everywhere, tinted glass jars of pills or liquids, and plenty of other things that were problem not legal--not even in wherever it was they were.