Sarah Jane (Elisabeth Sladen) mysteriously disappears – just as a huge meteor threatens to crash straight into Earth. When Maria (Yasmine Paige) wakes up one morning, it's as though Sarah Jane – and Luke (Tommy Knight) – never existed. Living across the road in Sarah Jane's house is a woman called Andrea (Jane Asher). And with the attic empty and Mr Smith (Alexander Armstrong) nowhere to be seen, every other trace of Sarah Jane has vanished – and Maria is the only one able to remember her. With the mysterious, hooded figure of the Trickster haunting Bannerman Road and the alien Graske meddling in time, Maria sets out to discover whatever happened to Sarah Jane. But as her journey takes her back to 1964, will she be able to find Sarah Jane in time to stop the meteor from destroying the world?

Maria (Yasmine Paige) finds herself taken back in time by the alien Graske to a pier in 1964. There, she meets a young girl her own age called Sarah Jane Smith (Elisabeth Sladen) who, with her friend Andrea (Jane Asher), is about to embark on a fateful adventure. Taken by the Graske again, Maria is then reunited with the present-day Sarah Jane. But with them both trapped in limbo as part of the meddlesome Trickster's plan to wreak chaos, they are helpless to stop the huge meteor which is about to crash into the Earth. Maria's dad Alan is the only one able to remember Sarah Jane and Maria and faces a struggle to bring them back in time to save the world.

When Sarah Jane finds a time fissure, her curiosity leads her to go through it and she finds herself in 1951, in the village of Foxgrove, where she was born. Eager to see the parents she never knew, she makes a decision that will have catastrophic consequences

With the Earth devastated under the control of the Trickster, Sarah Jane and Luke go back to 1951 and change things back to how they were- which means that Sarah Jane's parents must die. Will she make that sacrifice?

Mrs Wormwood returns to see Sarah Jane- but to ask help. The Bane have turned against Mrs Wormwood and are preparing to unleash a dark power against the universe. However, to thwart the Bane's plan, Sarah Jane must call upon an old friend

Luke's dreams are being tormented by visions of Mrs. Wormwood. The Sontarans are back for revenge. Sarah Jane must once agian call on an old friend.