‘Miss Smith, she seems familiar with the concept of alien life. Far too familiar.’ I’ve never bought the idea that a middle-aged woman is an unlikely lead for a children’s TV series: I grew up with Uncle Jack, T-Bag and Simon and the Witch among others. I like that The Sarah Jane Adventures is never shy about its central character, and I particularly like how she’s introduced as prickly, stand-offish and mysterious – just like the ninth Doctor. Or, looking further back, and acknowledging she ends up as the adoptive parent of an unearthly child, even Hartnellish. In her burgundy velvet coat, she’s even dressed like the third and fourth Doctors as she last saw them.

Following on from School Reunion, the launch episode is very much what Sarah Jane did next. It seems since re-meeting the Doctor she’s been making up for lost time, taking a subtler approach while Torchwood and UNIT go in ‘all guns blazing’. Elisabeth Sladen is predictably brilliant whether she’s brazening her way into Bubble Shock HQ like it’s Think Tank or bringing an unexpected insecurity as she bites her lip and tries to improvise her way to defeating an invasion of Earth without the support of the Doctor. If anything, she’s got a tougher gig than Christopher Eccleston or John Barrowman as she’s surrounded by child actors, by far the best of whom (in this) is Yasmin Paige. With no Billie Piper or Eve Myles to play off, she’s largely left to carry the piece.

Bits of this are very kid’s TV (Maria spotting a strange light and creeping out of her house at night is classic Secret Garden stuff), but this isn’t meant as a criticism. This is, after all, kid’s TV, and some of this approach feeds back into the parent show when Moffat takes over and children become central in a way they rarely were during the RTD run. But what’s more notable is how easily, with a few tweaks, this could have been made to work as an episode of Doctor Who. Replace Bubble Shock with Adipose pills and you’re already halfway to Partners in Crime.

The script is very funny (‘Hello Maria, hello screaming girl’ is my favourite). The guest cast is as impressive as an episode of the parent show. The scale is bigger than most Sarah Jane Adventures: scenes of zombified people wandering the streets of Ealing are exactly the kind of thing Doctor Who would do, reminding me of the Auton Invasion in Rose – an impression reinforced by the appearance of the Bane, which look like they come alive from the cover of the Terror of the Autons novel.

Invasion of the Bane’s main flaw is it’s a really good 45-minute episode crammed into an hour run time. It’s never dull, but it’s not quite as tight as an episode of Doctor Who. Mr Smith comes across like a less amusing replacement for K9 (off sealing a black hole / launching an Australian TV series). I wish Sarah Jane had christened the Archetype ‘Harry’, but that would probably have been too fannish. Taking some time to reflect on its strengths and weaknesses, boosting the cast and working out the best episode format ahead of the series all worked in the show’s favour, but this is a strong start. It’s the first indication that RTD was already thinking of a kind of Marvel Universe franchise for Doctor Who, with this show aimed at children as a primary school for the parent show’s secondary school (and Torchwood’s sixth form college). January 1st 2007 held the record to date for the most ever Doctor Who-related content broadcast on one day, with the final two episodes of Torchwood airing later in the evening. In retrospect, this is the start of the franchise’s imperial phase.

Sarah Jane will return in Revenge of the Slitheen – Part One

Next Time: Captain Jack Harkness