This episode is ever so slightly thin after the last four weeks. The main issue is that once the Doctor has convinced the Draconian Emperor that he’s telling the truth about the Ogrons, which happens around halfway, there’s nowhere much for the story to go until it ends next week. This results in a second half that is an extended spaceship chase sequence complete with lots of wobbling about action to simulate a battle. Hulke’s script is good enough that it never threatens to become tiresome – the Master’s ongoing reluctance to kill the Doctor, particularly at long range, is nicely done – but it does feel like killing time.

But even if on the whole this isn’t quite as strong as the earlier episodes, there are plenty of really good bits. The Doctor and Master’s audience with the Draconian Emperor (John Woodnutt doing a dry run for his iconic performance as Broton), in which the Doctor flashes his noble credentials while the Master sounds like a Radio 4 pseud: ‘Only during a period of social stability can society adequately deal with criminals such as this man and this unfortunate girl.’ And the Master’s evident frustration with his Ogron associates is very good (sadly he doesn’t get to say, “Why am I surrounded by fools?!”).

Back on Earth, General Williams and Madam President are still at loggerheads over how to deal with the escalating crisis. It’s actually more of a twist that Williams isn’t in on the Master’s plan, and is, in fact, convinced that the Draconians are warmongers based on a first encounter 20 years earlier when, in a plot replicated in Babylon 5, he mistook the arrival of a Draconian warship on a diplomatic mission as a sign that they were dangerous aggressors. In fact, as the Prince of Draconia belatedly explains, the warship was merely a signal of respect for the humans, and Williams has been living under a misapprehension for two decades. The General’s acceptance of this is a bit swift (and it seems odd the Draconians didn’t explain themselves sooner), but his pivot into supporting the expedition to the Ogron planet to uncover the truth is a triumph of reason and understanding over blind prejudice.

The episode ends with the Master and Jo’s arrival on Ogronworld, where Jo proves immune to the Master’s attempts at hypnosis (to his grudging respect), and a cliffhanger so abrupt it’s like they’ve just cut in the middle of a sentence.

Next episode: Frontier in Space – Episode Six