‘It’s Only Fools and Horses with green skin and claws.’ This is, in the end, very mildly disappointing. Partly it’s because a lot of the things that made Part One so effective, like Luke’s “parents” and Clyde’s investigations, get dropped in favour of a race against time to stop the Moon crashing into the Earth – just like the race against time to stop a meteor crashing into the Earth a fortnight ago. Which then calls into question why Mr Smith didn’t just “fail” to blow up that meteor rather than concocting this very convoluted plot.

It’s a shame, because there are a lot of things to like: Sarah Jane expelled from her own home, topping off losing her whole fam; Mr Smith’s origin story; the return of K9; Chrissie seeking some sort of resolution with Alan; Alan saving the day with his computer skills. Making Mr Smith villainous is a great (if well signposted) twist.

The only major casualty of making Alan a central character in the last few episodes of the series is a relative diminution in Maria and particularly Clyde’s contributions – Maria’s main role here is to earnestly pile the pressure on Alan and come up with an amusing but unlikely Only Fools simile (would kids in 2007 really jump straight to that cultural reference?), while Clyde spends most of it in a coma. This feels like the wrong call when Maria and Clyde are the juvenile leads. It is a slightly muted end to a first series that’s much more confident and consistent than Torchwood’s first year.

Sarah Jane will return in The Last Sontaran

Next Time: Voyage of the Damned