‘You speak treason!’ ‘Fluently.’ This is absolutely my cup of tea: horror with a sci-fi tinge, tea-time terror for tots. From childhood, I vividly remember the imp version of the Malus inside the TARDIS, vomiting up green bile. I’ve complained about the TARDIS being invaded too often in the last few seasons, and it does lose a bit of impact given practically everyone in the universe has traipsed through the control room by this point, but this is such a disturbing example it stands out. And the imp is just one iteration of a monster that, given it never really speaks, is one of the more robust and physical threats in this era of the show, and a welcome adjustment after the ethereal menaces of Season 20.

This isn’t perfect. Sometimes its status as a compressed four-parter shows through. Verney explaining the sci-fi plot to Turlough, for example, feels very much like dialogue reallocated from the Doctor in the interests of time. So does the Doctor inexplicably hurling himself into the arms of Sir George’s troops at the Maypole, and Sir George suddenly squealing that he has to go to the church because things need to wrap up. But I’d rather this than the rubbishy, “not enough time, can’t be bothered” second halves of Black Orchid and The King’s Demons.

I particularly love Davison in this. Something about his performance is channelling Troughton in The Five Doctors: the way he says, ‘Oh dear, oh dear’ and seems utterly unbothered by Jane flapping as mortal peril unfolds around them much as the second Doctor wasn’t fazed by being buried alive under the Tomb of Rassilon. He also gets to do jokes, including a very Bakerish line about speaking treason fluently, and the droll ‘toast of Little Hodcombe’ crack when he learns Tegan’s to be burned alive. In any case, the fifth Doctor’s vulnerability here manifests not as haplessness but as “making it up on the fly” and a willingness to admit when he doesn’t know something. And the way he towers over Polly James, in a (gags) pseudo-companion role (her business with Davison about the TARDIS door switch is lovely), makes him look almost Pertwee Mother Hen-ish.

This isn’t the greatest story of the era, and it’s not quite eerie enough to qualify as true folk horror, but I wish the season had opened with it (an obsession with the continuity of the Doctor’s new costume – which isn’t commented on anyway – probably nixed any possibility) because it’s so energetic, screaming “Doctor Who is back” much more effectively than the downbeat, undercooked Warriors of the Deep. Smashing.

Next episode: Frontios