Sarah Jane, Luke, Clyde and Rani face an old enemy, the green Slitheen, in the penultimate episode of this series of The Sarah Jane Adventures.
When the Slitheen's latest scheme is halted, their rivals, the Blathereen, arrive. Declaring peace between the planets, they offer Sarah Jane a gift – one that might change the future of the human race forever.
The second part airs the next day:
When the Blathereens' gift runs riot, Sarah Jane faces the battle of her life to save her son, Luke, as The Sarah Jane Adventures concludes.
With Clyde, Rani and K9 trapped in a school under siege, and the whole of London convulsing under the alien threat, everything heads for a final showdown in the attic – and not everyone is getting out alive.
Sarah Jane Smith is played by Elisabeth Sladen, Luke Smith by Tommy Knight, Clyde Langer by Daniel Anthony and Rani Chandra by Anjli Mohindra. John Leeson provides the voice of K9.