This is the one with the giant rat cliffhanger, the second-most regrettable thing about the story. Which, given it’s on screen for about 3 seconds mostly in shadow, is barely a criticism at all. For the most part, this is every bit as strong as the previous two episodes, and shows no sign of mid-serial doldrums.

What it does show is a fairly flagrant disregard for all the restraint you’d normally expect from Doctor Who. This obviously extends to the money Hinchliffe splashed out which, allegedly, blew the series budget and landed incoming producer Graham Williams with problems throughout his tenure. So as well as the night filming, we get the Doctor and Litefoot messing about in a boat as they hunt the rat, which looks gorgeous even if it’s not strictly necessary to tell the story.

It also extends to the script, which is Robert Holmes unbound, revelling in its grand guignol excesses and including a blatant, if unspoken, depiction of prostitution with ‘despicable Chang’ approaching a ‘budding lotus of the dawn’. Kidnapped women are stripped to their underwear and treated like pieces of meat for Greel to feast on: ‘contemptible slatterns,’ Greel calls them before declaring Leela has ‘muscles like a horse.’

The script obviously comes down very firmly on the women’s side. ‘They are missed,’ a worried Chang warns his master. But Greel is ‘a blaggard’, a ‘slavering gangrenous vampire’ whose vaguely unspecified scientific knowledge includes the ability to make things grow huge, extract life energy from the abducted prostitutes, and make experimental trips through time – an all-purpose biologist, chemist and physicist. Close to death, feasting on the vitality of nubile flesh, he’s pretty much the summation of all Hinchliffe era villains: megalomaniac. deformed, masked, and reliant on his long-suffering servants to move where he cannot. There’s a clear link to the Master, who was briefly considered for inclusion (and the Time Cabinet/TARDIS and Time Agent/Time Lord similarities are pretty apparent). But, really, he’s as much Davros, or Morbius, or Sutekh, but perhaps more horrible because his victims are so much more helpless.

Next episode: The Talons of Weng-Chiang – Part Four