In the story, Sarah Jane Smith is emotionally manipulated by a malicious chaos-causing entity called The Trickster into preventing the accidental death of her parents in the past, in order to open a fault in time and bring chaos upon the Earth.
Ignoring Luke's warning that changing time is not a good idea, she sabotages her parents' car with her sonic lipstick to prevent them from leaving.
In the present, the Verron puzzle box Maria used[N 1] lights up, and Clyde and Rani are transported to London in an alternative timeline in which the Trickster physically entered the world in 1951 and destroyed it because Sarah Jane broke a faultline in a weak point in time located in the village.
In the present, the last of humanity is enslaved by Krislok, and are mining resources so that the Trickster may create a ship and extend his reach to the rest of the universe.
Clyde promises Krislok that if he helps them get back to Sarah Jane, they will give him the puzzle box to free him from the Trickster.