Any qualms that might have been held about Moffat and Gatiss not delivering the script for this one themselves should be forgotten by the time the credits roll. That said, if it’s even possible to disentangle the two, The Reichenbach Fall is an episode where the performances eclipse the writing.

Martin Freeman is heartbreakingly good at showing Watson’s repressed vulnerability, and Benedict Cumberbatch displays a broader emotional range than we’ve yet seen from his Sherlock whilst maintaining the mask of a controlled rationalist. The Hounds of Baskerville showed Holmes in the grip of terror, but The Reichenbach Fall has him facing up to horror.

The source of that horror? Well, that would be telling, but you can more or less guess whose hand has orchestrated the checkmate Holmes is placed in towards the end of the episode.

So far, series 2 of Sherlock has foregrounded Sherlock’s relationships, and The Reichenbach Fall is no different. This time it’s not Sherlock’s best friend, love interest, brother or housekeeper under the spotlight, but his nemesis.

Andrew Scott is a delicious Moriarty. Clearly insane, clearly a genius and clearly every bit as obsessed with Sherlock as Adler was, Scott exudes menace. It’s all in those eyes.