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.
As the Doctor makes changes to the film script, a control room (a Cyber-infiltration unit) records his suggestions and evaluates their success rate for an invasion of Earth. The Cybermen have been monitoring the film's progress through an implant in Kate's skull that they put in her last year when they kidnapped her. After several changes to the script, the success rate for invasion reaches 100 percent. However, the Doctor has been aware of this all along, enters the control room, and suggests the Cybermen leave Earth before UNIT arrives to destroy them.
Kate undergoes a successful surgery to remove the implant (and her tonsils).
- Some of the changes the Doctor makes to the script include:
- The Doctor uses the alias John Smith.
- A man named Michael is playing Tobias Vaughn in the film.
to be added