‘A perfect fifth.’ While making Doctor Who, Davison was also recording two sitcoms (Sink or Swim for the BBC and Holding the Fort for ITV, and there was a two-month break between the recording of The Visitation and Kinda to allow Davison time to tape Sink or Swim. Maybe the gap gave him chance to assess what he wanted to do with the role, because his performance here is a lot more confident than in Four to Doomsday, bringing the familiar elements of fraying patience, insouciance and sudden manic bursts of energy that characterise the fifth Doctor. Or maybe it’s just that this was conceived for Tom Baker, and Davison’s responding to a script that includes jokes (‘An apple a day keeps the.. Never mind.’) and casual authority.

After two serials with very shaky first halves, this gets it right, mixing a familiar Doctor Who plot with the surreal SF of Tegan’s trip inside her own mind. It might be a base under the nicest siege ever, but its crew’s cracking up as obviously as any Troughton-era outpost’s. I enjoy the strange parallels between the cut-down TARDIS crew (Nyssa’s having a nap like she’s Hartnell on an off week) and the base crew – the Doctor ticks off Adric just like Sanders belittles Hindle, while the women, Tegan and Todd, seem more open to the culture of the Kinda. I enjoy the Doctor snapping at Adric for running a stick along the wind chimes, then a couple of minutes later doing exactly the same thing himself.

While the men are taken into the dome to face Sanders’ denial and Hindle’s nervous breakdown, Tegan’s taken into a black void to confront characters that look like they’ve wandered out of a German expressionist film. They can be cleverly analysed, but there’s also a simple point to these scenes: they’re creepy as hell, and taken with the nutty behaviour of the men in the dome and that brilliant cliffhanger, combine to tell a story of tropical madness consuming the colonisers. Heart of Darkness done in Television Centre.

Next episode: Kinda – Part Two