The TARDIS lands on a derelict vessel floating on the sea of an alien world almost completely covered by water.

She relives some of her most terrible memories, including her sexual abuse at the hands of her stepfather, in a desperate attempt to retain her identity and individuality.

Forward stated that the change in the final manuscript was made at the request of editor David J. Howe, who thought it would be better to link the story to a fan theory about Peri's relationship with her stepfather, though not based on her character as seen in the television serials.

The Doctor, meanwhile, has been rescued by a giant crab called Scrounger, who was designed to fight in a war but is now surviving with others of his kind on a nearby island.

The Doctor tries to organise the remaining crabs into a defence, and Scrounger is sent to find medical supplies in the sunken derelict.

The female causes an aggressive response from Ranger, who drives her away, but soon they have other things to worry about: Meathook's army has arrived.

The two remaining groups of crabs join forces, and the Doctor advises them to let the Memory heal and help them build a new society.