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?