After the TARDIS collides with a spacecraft delivering human tributes to the evil bull-like Nimon, the Doctor and Romana must stop the fearsome alien's quest to rule the galaxy.

An American actor in England tries to find love and work.

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.