Stripped of the poignancy surrounding the tragic death of its leading lady and viewed on its own merits, the final series of The Sarah Jane Adventures opens with the same combination of explosive action, snappy one-liners and quintessentially English charm that has made the programme so popular with children and a guilty pleasure for older Doctor Who fans reliving their long-forgotten youth.

However, the show’s more grownup viewers will find it difficult to watch without remembering that Elisabeth Sladen is no longer with us, and that these six episodes are the last bow of a wonderful actress who has charmed successive generations since 1973.

‘Is there anything more beautiful than a star-filled sky?’ Sarah Jane ponders in voiceover at the beginning. ‘As a child, I would dream of what might be up there, but never imagined that one day, I would find out.’ It’s an elegiac opening to the episode, but the introspection doesn’t last long. Soon, there’s a meteor exploding into a local wrecker’s yard early one Sunday morning, smashing up piles of rusting cars and disturbing a homeless man dressed like a destitute William Hartnell.

A metal creature emerges from the pyrotechnics, looking like a drunken, wild-eyed Cyberman on steroids (this is a good thing), and promptly makes itself invisible. At the same time, Sarah discovers something unexpected on her doorstep: something which looks cute and innocent but just happens to have a knack of blowing all the light-bulbs out on Bannerman Road, exploding all of Sarah’s computers (‘Mr Smith won’t come out – well, would you if you were going to get your circuits fried?’) and making car alarms ring endlessly.

Finally, at the nearby Summerwell Nuclear Power Station, a voluptuous blonde named Miss Myers (Christine Stephen-Daly) emerges from a blue bubble of energy, zapping the gaping male staff with a River Song-ish ‘Take a power nap, boys’ and striding out in search of the mysterious arrival at Sarah Jane’s house, fur coat billowing out behind her. ‘Just a regular day on Bannerman Road,’ Rani’s dad remarks wryly.

With Sarah’s son Luke still away at university – although he does appear briefly via Skype – it’s once again up to Clyde and Rani to take up the mantle of Sarah Jane’s principal assistants. Daniel Anthony and Anjli Mohindra have come a long way since their first appearances and are as comfortable with the physical sequences – chases through junkyards and power stations – as they are with dispensing the wisecracks. ‘What have you been living on – battery bunnies?’ Rani asks the homeless man who witnessed the meteor strike. ‘Oven chips are the work of bad, twicky goblins,’ Clyde observes apropos of nothing.

Yet despite the able support of the regulars and guests, it’s Elisabeth Sladen who leads from the front. Speculation about her health during the making of these final episodes is as inevitable as it is unnecessary, but in this opening instalment she appears in as fine and feisty fettle as ever, stalking boldly into danger and adventure with only her sonic lipstick and her teenage companions for company – ‘never careful, always prepared.’ It’s great to have her back, even if it’s only for a little while.

Airs at 5.15pm on Monday 3rd October 2011 on CBBC.

> Buy the Series 4 boxset on Amazon.

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