Charged with genocide by the treacherous Valeyard at his trial, the Doctor receives help from an unlikely source to turn the tide of the High Council's rulings in his favour and reveal the Valeyard as a wrongdoer: the Master. For the Valeyard's own crimes are so atrocious, even the Doctor's archenemy will help him to ensure that the villain won't see the light of day again. Cornered, the Valeyard flees to the Matrix, where he can be the Doctor's judge, jury and executioner...
| Directing | Chris Clough | Director |
| Writing | Robert Holmes | Writer |
| Writing | Jane Baker | Writer |
| Writing | Pip Baker | Writer |
| Writing | Eric Saward | Script Editor |
| Production | John Nathan-Turner | Producer |
| Writing | John Nathan-Turner | Script Editor |
| Costume & Make-Up | Andrew Rose | Costume Design |
| Art | Michael Trevor | Production Design |
| Sound | Dominic Glynn | Original Music Composer |
| Costume & Make-Up | Shaunna Harrison | Makeup Artist |
| Production | Jane Wellesley | Production Assistant |
| Production | Ian Fraser | Production Manager |
| Crew | Dick Mills | Special Sound Effects |
| Camera | Alec Wheal | Camera Supervisor |
| Lighting | Don Babbage | Lighting Director |
| Sound | Brian Clark | Sound |
| Lighting | John Mason | Lighting Director |
| Sound | Vic Godrich | Sound |
| Visual Effects | Dave Chapman | Visual Effects |
| Visual Effects | Danny Popkin | Visual Effects |
| Editing | Hugh Parson | Editor |
| Visual Effects | Kevin Molloy | Visual Effects |
