‘I can’t believe you were going to save those Slitheen. They tried to destroy the entire planet. Billions of people. What was the big dilemma?’ Clyde is a brilliant character. Not for him the hand-wringing angst of so many modern Doctor Who characters. Instead, he’s full of Old Testament piss and vinegar. Literally, in the case of the vinegar – a critical element of the fight back against the Slitheen which he smartly works out from a few hints, justifying his position as the fourth member of Sarah Jane’s extended family.

Not that Sarah Jane initially sees it that way: she doesn’t want to be responsible for him: ‘Someone else’s life in my hands. Just what I needed.’ I like this side of Sarah Jane: a guarded privacy, a brittleness that perhaps comes from decades of having to adjust to life after the TARDIS, unable to share her experiences with anyone else. It’s reminiscent of the ninth Doctor in Rose: brusque to the point of rudeness, pushing people away, afraid to be vulnerable.

The solution to this is Luke, who is gradually moving from thinking of her as ‘Sarah Jane’ to ‘mum’ Their tentative attempts to form a parent/child relationship are very sweet, providing emotional heft to an episode that focuses heavily on such relationships. Chrissie Jackson treats Maria with casual disinterest, taking for granted what Sarah Jane is too uncertain to discuss. Clyde’s dad is absent. Which, aside from Alan and Maria’s, makes Kist Slitheen’s relationship with his son Korst the most functional in the piece: ‘We are doing this for our children,’ as he reminds Glune.

This is very good. It has enough references to the past (Sarah Jane recalling Rose Tyler’s mention of the Slitheen in Downing Street; UNIT; Trinity Wells) to provide a clear connection to the parent show, while planting enough seeds for the future (Korst clearly teleports away before he messily explodes in bloody chunks like Florm; Mr Smith has a malevolent moment when Clyde gets too curious) to hint at a wider shape to the series.

Next Time: Eye of the Gorgon – Part One