Sometimes, when Sherlock gets into one of his moods, the best thing to do is just to let him vent. Let him rant and rave and stomp about, and eventually he'll run out of steam.

And that is exactly what John is doing right now. Sherlock came home from Bart's in a snit, and is now stomping and gesticulating, muttering about "incompetence" and "trained monkeys" and who knows what else. Every so often he turns to John, as if for encouragement, and John merely nods. Sherlock, of course, takes this as validation for his ire, and continues grumbling and kicking piles of paper as he goes.

Eventually, he wears himself out and flops onto the sofa violently enough to cause it to bump into the wall. Not one to let mere physical fatigue get the better of him, Sherlock continues to bluster and fume, having run seamlessly from complaining about Anderson in particular to a diatribe on the general uselessness of the modern police force in general.

Picking up his tea mug, John makes a point of neither encouraging nor discouraging his giant toddler of a flatmate. Sherlock, in response, increases both the volume and the pitch of his grumbling, and John simply turns the radio up and goes back to his newspaper, the smile on his face passive and bland.