It’s still a thrill to be able to watch this episode, missing for 40-odd years. The story is full of notable first and lasts – Barry Letts’ first credit on the programme; the first episodes to be recorded in the new 625-line standard (which makes them look a lot sharper than the old 405-line recordings – this is the HD Planet of the Dead of the classic series). It’s also the last story to be produced by Innes Lloyd and overseen by Sydney Newman – the men who were instrumental in bringing in Troughton and helping him to shape his performance.

As such, it’s a nice coincidence that Troughton is established enough as the Doctor that a story with an identical double can be attempted. Immediately, I get the sense that this is The Massacre done as John Lucarotti originally intended: where the Doctor is not only aware, but is an unwilling participant in a deception to use his similarity to the baddie to foil him. And just as the first Doctor is reluctant to be pulled into the plots and counter-plots of Reformation France (at least in Lucarotti’s novel) so here the second Doctor is practically forced at gunpoint to imitate Leader Salamander.

Like The Massacre, this is much more political than usual. Whereas The Ice Warriors revolved around the concepts of man versus machine, this is rooted in recognisable 20th Century power struggles, where enemies of the state are routinely “disappeared” and rival factions vie for control. Giles Kent isn’t set up as a noble hero – he’s a discredited opponent of Salamander, and the Doctor has very little interest in getting involved with either side when neither seems to be especially appealing. This ambivalence is refreshing in this era of the show, when good and evil are usually quite clear cut, and immediately makes this more intriguing to me than the previous story.

It helps that the episode has more action in its first 10 minutes than The Ice Warriors had in 150. Almost half the run time is on film, looking like a budget ITC serial complete with a hovercraft, a helicopter, a shoot-out and a huge explosion. Rather than front-loading exposition, writer David Whitaker hooks us with incident and follows up with explanation – a huge change from most earlier Doctor Who that explains what is going to happen before attempting to show it.

Likewise, Whitaker’s characters are more vividly drawn, with Astrid fitting very much into the no-nonsense female role of The Avengers, and Kent coming across as a slippery politician. The choice of look for Bruce is quite telling: dressed and built like a blackshirt thug, but peering over his spectacles like a stern headmaster. Jamie and Victoria don’t get much to do, but Hines and Watling are great at playing exasperated amusement with the Troughton.

And Troughton – obviously relishing a dual role, and some great lines – plays the Doctor with incredible lightness and precision (his evasiveness when Astrid’s trying to establish what he’s a doctor of is brilliant), in contrast to Salamander, who looks like a fascist, but with a kind of indolent superiority (the arm gestures are slow, he seems amused by his own power, rather than filled with rage).

This is a great first episode, full of intrigue and action, interesting characters and a well-established situation. My only criticism is that Whitaker should have leaned into the James Bond overtones and called it Suncatcher.

Next episode: The Enemy of the World – Episode 2