The Sarah Jane Adventures: The Lost Boy

This story is a bit like a delicious, but crumbly, cake. The ingredients all taste great, but the final thing just won't hold together.

Let's begin at the beginning. The Slitheen are back. They've always been a bit too panto to feel like a real threat, but they do carry the weight of having been the baddies who opened this series.

The Slitheen want to kidnap Luke to harness his latent telekinetic powers. So, how to go about it? Do they kidnap him after school and bundle him into a car? Poison him with a sleeper drug? Maybe they should simply use their so-often forgotten teleport?

Or should they disguise themselves as a human married couple, go on the news, claim that Luke is their child who went missing five months ago, fake an entire false history for him including photos, convince the entire main cast of it against their own personal experiences, and then force Sarah Jane to hand him over legally?

Ohhh... dear.

One of the things that enables me to forgive such a truly dreadful story is the way it's played-out. At the start of episode one, we don't know anything about the Slitheen's plot, so we get it all from poor Sarah's point of view.

The whole awful sequence of events, as she sees the grieving couple on the news, carries out her own checks, and it slowly dawns on her that she's spent the past five months actually being a child-abductor, is such edgey material that it's brilliant.

As Sarah endures losing her beloved adopted son, faces all the typical knee-jerk judgement from Luke's arrogant 'real' family, gets publicly arrested in front of all the other children and parents who she's befriended this series, and is driven off into police custody to presumably spend the rest of her life in prison, Sarah's composure is riveting, and defining.

This is the lead character in a series on children's television.

Sarah loses her faith in herself, and the friends who we've grown to love over the past eight weeks are forced to split up.

When Maria's dad finds out about his daughter's recent life-or-death battles to save the planet, sure enough, he decides to move them both away to a new town. This is the real world crashing in and ruining everything, alright.

And then Sarah's computer turns out to have been evil all along, and has orchestrated the whole thing, resulting in part one's cliffhanger ending – a close-up of its computer screen maliciously chuckling.

Oh yes, it's definitely end-of-season stuff. And after all that drama, I find myself unexpectedly reaching for that panto word again...

The second half absolutely races along, and with so many mad elements in play, it was hard to believe that we weren't heading for an even bigger end-of-season cliffhanger. What we got instead was a spectacular series of breakneck sequences that, really, in no way tied everything up, but were wall-to-wall excitement and fun anyway.

Even Sarah's robot dog - K-9 - comes back for a laser shoot-out with evil computer Mr Smith, quietly ignoring the rules that were laid-down to prevent his return back in the pilot. Why does Chrissie wordlessly accept that Luke is back with "that child-snatching maniac" Sarah again at the end? Why does noone suspect the Trixster at the beginning? Why didn't image-faking Mr Smith kill Clyde? Wha' haaaaappened?

Oh, but I just don't care. So much fun put me in such a good mood that I'm even prepared to let the old computer-virus solution go by, and accept Alan's convenient explanation for where he'd got it from.

The majority of this series has been so good that I feel it's earned the right to a certain amount of mindlessness. Certainly not this much every week, but if they can make three strong stories out of five again next season, and be this unpatronising about it, then I'm definitely in.