With the prosecution case concluded, at last the Doctor is able to present his evidence. It takes place in the future with a new companion and new problems.

As the Hyperion III continues its journey, more mysterious deaths occur.

A course change that takes the Hyperion III closer to a black hole could prove unwise when there are so many aboard ship with hidden agendas. Disappearances continue, a murderer remains at large, and one person finally crumbles under the strain of harbouring a guilty secret.

With factions vying for control of the ship, the Vervoids are found to be responsible for the many disappearances. Only the Doctor sees the fundamental but missed point as to why they can't be reasoned with or why they can't be allowed to arrive on Earth.