As evidence for the defense at his ongoing trial, the Doctor presents an adventure from his future when he is travelling with a computer programmer named Mel. Answering a mysterious distress call from the space liner Hyperion III, they find that the passengers aboard include unscrupulous scientists, secret agents, saboteurs, thieves and a murderer. And lurking in the shadows are the Vervoids, the product of sinister botanical experiments, who will stop at nothing to destroy all non-plant life.
| Writing | Jane Baker | Writer |
| Writing | Pip Baker | Writer |
| Directing | Chris Clough | Director |
| Production | John Nathan-Turner | Producer |
| Writing | John Nathan-Turner | Script Editor |
| Sound | Malcolm Clarke | Original Music Composer |
| Camera | Alec Wheal | Camera Supervisor |
| Costume & Make-Up | Andrew Rose | Costume Design |
| Art | Dinah Walker | Production Design |
| Costume & Make-Up | Shaunna Harrison | Makeup Artist |
| Production | Jane Wellesley | Production Assistant |
| Production | Ian Fraser | Production Manager |
| Crew | Dick Mills | Special Sound Effects |
| Lighting | Don Babbage | Lighting Director |
| Sound | Brian Clark | Sound |
| Visual Effects | Danny Popkin | Visual Effects |
| Editing | Hugh Parson | Editor |
| Visual Effects | Kevin Molloy | Visual Effects |
