 This episode, along with "Utopia" and "Last of the Time Lords", are treated in several sources as a three-part story, the first such story in the revived series of "Doctor Who".However, Russell T Davies has said that he regards "Utopia" as a separate story, but notes that the determination is arbitrary.Some of the car action sequences in this episode were filmed by Freema Agyeman herself rather than a stunt double, and took place at Harbour View Road, Penarth.