Lloyd Kingsley-Sayle is filming a movie about the Cybermen invasion of the 1970s. At the request of Brigadier Lethbridge-Stewart, the Second Doctor poses as a scientific advisor on the set. The Brigadier is concerned that the movie will reveal too much about UNIT. The Doctor "corrects" events in the film while also making friends with Lloyd's seven-year-old daughter Kate. Kate had been kidnapped for a week last year and returned mysteriously. Kate undergoes a successful surgery to remove the implant (and her tonsils).