In 17th century England, the Doctor and itinerant thespian Richard Mace uncover a plot by a crew of criminal Terileptils to wipe out humanity.
| Directing | Peter Moffatt | Director |
| Writing | Eric Saward | Writer |
| Production | John Nathan-Turner | Producer |
| Writing | Antony Root | Script Editor |
| Sound | Paddy Kingsland | Music |
| Costume & Make-Up | Odile Dicks-Mireaux | Costume Design |
| Art | Ken Starkey | Production Design |
| Camera | Peter Chapman | Camera Operator |
| Editing | Ken Bilton | Editor |
| Sound | Stan Nightingale | Sound |
| Costume & Make-Up | Carolyn Perry | Makeup Artist |
| Crew | Dick Mills | Special Sound Effects |
| Lighting | Henry Barber | Lighting Director |
| Sound | Alan Machin | Sound |
| Editing | Rod Waldron | Editor |
| Crew | Peter Wragg | Special Effects |
| Visual Effects | Dave Jervis | Visual Effects |
| Production | Julia Randall | Production Assistant |
