While investigating a vanishing Concorde at Heathrow Airport, the Doctor and his companions are thrown millions of years back in time, when a mysterious alien called Kalid is trying to control the ancient powers of the Xeraphin.
| Writing | Peter Grimwade | Writer |
| Directing | Ron Jones | Director |
| Production | John Nathan-Turner | Producer |
| Sound | John Gatland | Sound |
| Editing | Mike Houghton | Editor |
| Writing | Eric Saward | Script Editor |
| Sound | Martin Ridout | Sound |
| Sound | Roger Limb | Original Music Composer |
| Lighting | Eric Wallis | Lighting Director |
| Camera | Peter Chapman | Camera Operator |
| Costume & Make-Up | Dorka Nieradzik | Makeup Artist |
| Costume & Make-Up | Amy Roberts | Costume Design |
| Crew | Dick Mills | Special Sound Effects |
| Editing | Rod Waldron | Editor |
| Art | Richard McManan-Smith | Production Design |
| Production | Joan Elliott | Production Assistant |
| Visual Effects | Dave Chapman | Visual Effects |
| Visual Effects | Peter Logan | Visual Effects Designer |
