N.B. there might (or might not) be spoilers in this article!

So Mr Smith’s been plotting this all along? The b*stard.

For the second story in a row, the peril is ultimately caused by something hurtling towards Earth. In Whatever Happened to Sarah Jane?, it was a meteor and Mr Smith was required to stop it — something he couldn’t do if he didn’t exist, due to there being no Sarah Jane! In The Lost Boy, it’s the moon on a collision course with Earth — and apparently it was Mr Smith’s evil plan all along.

As I said – the b*stard.

“Same Slitheen, different skin,”

Nathan, The Lost Boy, Part One

The episode kicks off on a neat premise — the idea that Luke might have been somebody else’s child all along (even if I did wonder why it would take five months for the parents to post a picture of their missing child) — and builds solidly to the first episode’s revelatory cliffhanger that Mr Smith is behind it all.

Along the way the Slitheen make their second appearance of the season, Sarah Jane goes all action hero(ine) when fleeing the Pharos Institute, Clyde gets lost in the matrix, and Maria memorably describes the Slitheen’s dodgy dealings as ‘Only Fools and Horses with green skin and claws.’

I think my favourite line, though, has to be Sarah Jane’s, who upon hearing Alan is out of vinegar — Slitheen Kryptonite — remarks: ‘Oh, then we may have to stop off at a chip shop.”

Overall, The Lost Boy offers a strong finale to what has been an excellent first series of The Sarah Jane Adventures. Maria, in bringing Dad Alan up to speed, provides us with a nice recap of the events early on, and Sarah Jane, after briefly returning to her ‘frosty’ self from Invasion of the Bane, realises that over the course of her adventures with the Jacksons and Clyde that she’s found a family, something she never expected.