‘How do you kill death?’ The same way you kill an intelligent super-virus or a Rutan, it seems: blow it up. I’m hoping Anthony Read turns out to be better at workshopping endings than Robert Holmes is. The Fendahl turns out to be Wanda Ventham painted gold and doing callisthenics, and some giant slugs that are as susceptible to salt as the common-or-garden variety. How tarsome.

Still, it looks better than The Invisible Enemy, George Spenton-Foster directs it well, and there’s nothing as embarrassing as the Nucleus, so thank goodness for small mercies. Thea’s transformation is cleverly achieved, and Max gets a memorably horrid death. That this turns out to be another botched intervention by the Time Lords is interesting given what’s coming up later in this season, and helps paves the way for Graham Williams to introduce the new gods of time in the next. And I adore Martha Tyler: another of the Tom Baker years’ batty old women.

Basically, there’s enough here to make this worthwhile, even if it’s easily Chris Boucher’s weakest script. The Face of Evil was all about the Doctor facing the consequences of past actions; The Robots of Death put him in the Sherlock Holmes role. He barely does anything in this: it takes an episode to arrive at Fetch Priory, one scene with the main protagonists, and an episode faffing about in the TARDIS. When Tom Baker gets anything to do, he’s very good – I love the moment in this episode where he pushes his hat back to take a shot at an advancing Fendahleen – but he’s largely just there to gush exposition and do something clever with wires at the end. This is a serial summed up by the Doctor pressing a switch and declaring, ‘Well, I’ve saved the planet.’

When I was a Time Tot, I was fascinated by this story, largely on the basis of the evocative publicity photos included in the Radio Times 20th Anniversary Special, and then by the grotesquely lurid cover of the novelisation, which I picked up from a second-hand bookshop in Hay-on-Wye. I’ve always been a bit disappointed that the experience of watching it never lives up to how I imagined the creeping horror of the Fendahleen, the most Lovecraftian monsters in years. Sadly, my opinion remains unchanged. It gets the fundamentals right: it’s fun, it looks good, it’s entertaining enough, but it fails to give the Doctor and Leela a proper role in the plot, and as there’s nothing more substantial than the atmosphere it all sort of dissipates to nothing: “fur coat and no knickers” as mum would say.

Next episode: The Sun Makers