Up until thirty minutes ago, John was feeling incredibly cross with Sherlock. All he wanted was to invite his best friend over for their sodding Thanksgiving meal next week, but he was being so obtuse about the whole thing that John couldn't help but react with anger. Being difficult is nothing unusual for Sherlock, but John has been nursing a grudge ever since Mary alluded to him telling her about the incident with Magnussen before he could approach her about it himself.

As a result, John was prepared to go over and have it out until Mary stepped in, shedding some insight on how he might be feeling based on her interactions with him. It made John think more rationally and, as a result, he has put his anger on the back burner for now. Unintentionally or not, John has made himself unavailable lately. One of the cons of planning a second wedding and months of domestication that should have him chomping at the bit.

So, after a quick detour to another government housing building nearby, John raps his knuckles against the door and waits.