The Sarah Jane Adventures - Season 1 Episode 7

Visiting Sarah Jane Maria is shocked to find her place taken by Andrea, a woman of the same age group who has apparently lived in the house for years. A newspaper from over forty years earlier reveals that Sarah Jane, then 13, fell to her death from a pier where she and Andrea were playing. When Maria confronts her with this Andrea goes to her attic and conjures up a cloaked figure, the Trickster, who sends a dwarf called the Graske to transport Maria back to 1964, where she meets schoolgirls Andrea and Sarah Jane.