A warp ellipse draws the TARDIS off course. The Fifth Doctor's companions are separated from him not in space, but in time, and he has to deal with a treacherous schoolboy named Turlough. But why does the Doctor's old friend, the Brigadier, not remember him at all?
Unfortunately the movie Doctor Who: Mawdryn Undead is not yet available on HBO Max.
| Directing | Peter Moffatt | Director |
| Writing | Peter Grimwade | Writer |
| Art | Stephen Scott | Production Design |
| Camera | Godfrey Johnson | Camera Operator |
| Costume & Make-Up | Amy Roberts | Costume Design |
| Editing | Chris Woolley | Editor |
| Sound | Paddy Kingsland | Original Music Composer |
| Sound | Ron Brown | Sound |
| Costume & Make-Up | Sheelagh Wells | Makeup Artist |
| Costume & Make-Up | Carolyn Perry | Makeup Artist |
| Production | Valerie Letley | Production Assistant |
| Production | June Collins | Production Assistant |
| Production | Ann Aronsohn | Production Manager |
| Camera | Robin Barnes | Camera Supervisor |
| Lighting | Don Babbage | Lighting Director |
| Sound | Martin Ridout | Sound |
| Crew | Dick Mills | Special Sound Effects |
| Crew | Alan Arbuthnott | Technical Supervisor |
| Sound | Peter Howell | Theme Song Performance |
| Visual Effects | Robin Lobb | Visual Effects |
| Editing | Rod Waldron | Editor |
| Visual Effects | Stuart Brisdon | Visual Effects Designer |
| Writing | Eric Saward | Script Editor |
| Production | John Nathan-Turner | Producer |
