The show’s new mission statement is introduced with considerable style as the Doctor and K9 MII’s plans for a holiday are interrupted by crashing organ chords announcing the arrival of the White Guardian. With the Time Lords comprehensively debunked, apparently Graham Williams felt the Doctor needed a new “higher authority” he was accountable to. What we get is an ageing white man who feels that things have gone too far into permissiveness and chaos, and that order needs to be restored – a back-to-basics approach for the universe, which can only be achieved through assembling the six segments of the Key to Time (or ‘of Time’, the script isn’t sure).

It’s a great opening for the new series, in its own way as ambitious as Barry Letts’ refocusing of the show in Season Eight. Like the Time Lord in Terror of the Autons, the White Guardian warns the Doctor of a new villain (the unfortunately-named Black Guardian). Like Letts, Williams takes the opportunity to introduce a new assistant: the statuesque Romana, played by Mary Tamm as a precocious know-all who delights in bringing the Doctor down a peg or two. While she has a nice line in sarcastic asides, her cool competence allows Baker more leeway to lean into the comic take on the Doctor he started to develop the previous year. And Like Letts, Williams turns to Robert Holmes to write the launch serial for his new vision.

The result is a classic script that lightly establishes the new set up, before switching its focus to the planet Ribos which, in true Game of Thrones style, has an eccentric orbit and very long summers and winters. Presumably learning from the production nightmares of Season 15, Holmes also makes sure the planet is exactly the kind of place that can be achieved with the show’s constrained budget – that is, it’s an alien planet that largely looks like something out of Earth’s history. So, no cheap-looking sci-fi smocks or beige corridors. The result is the best the series has looked since Horror of Fang Rock and Image of the Fendahl.

The comedy, similarly, is much more in the vein of the badinage of The Sun Makers than the burlesque of The Invisible Enemy, and is genuinely built around a series of double acts (the Doctor and Romana, Garron and Unstoffe, Graff and Sholakh) with supporting characters occasionally wandering in. This episode mostly focuses on the Graff’s dreams of conquest, and Garron’s gloriously seedy plans to con him. Meanwhile, the Doctor and Romana head straight for the first segment of the Key and are menaced by the floppy shrivenzale, the one element of the script that was beyond the resources of the BBC.

One thing I noticed: the script strongly implies Borusa is now the President of Gallifrey given he knows the Doctor’s grades at the Academy, and was present during the Sontaran invasion (the Doctor says ‘I should have thrown him to the Sontarans when I had the chance’).

Next episode: The Ribos Operation – Part Two