Sherlock is sprawled extravagantly on the couch, flat on his back with one foot on the armrest and the other braced firmly on the floor. John, the traitor, has gone to Sarah's. Boring, predictable Sarah – Sherlock always conveniently forgets how she held her own during that first evening at the Chinese circus when he's pouting like this. They're inevitably doing something boring and predictable, like seeing a film and going to dinner. Anywhere but Angelo's, Sherlock finds himself thinking. He also derives sudden, irrational glee from the notion that John will again be sleeping on the sofa.
He has been attempting to work out a particularly complex series of clues, and keeps mentally running in circles, to his immense frustration. He scowls petulantly at the skull, who is tiresome and a terrible replacement for John. How selfish of him to have left in the middle of a case, he knows how much Sherlock depends on him as a sounding board. John knows, of course, doesn't he? Sherlock shouldn't have to tell him he is appreciated, necessary. John is a relatively smart man; he should be able to figure these things out.
Sherlock, for all his incredible brain power and deductive reasoning still cannot determine why the temporary loss of one small, solid, army doctor can leave him feeling so absolutely bereft.
