Barbara and Ian Look Down on the Crashed Spaceship

With The Doctor, Barbara Wright and Ian Chesterton still feeling the effects of leaving Susan behind in 22nd-century London the TARDIS materialises on a planet. The Doctor eventually recognises as Dido, a world he has visited before.

The three time travellers soon spot in the distance a crashed spaceship from Earth. Inside they discover it has two occupants - a paralysed man named Bennett and a young girl called Vicki. Both of whom are waiting for a rescue ship that is due to arrive in three days time.

They also learn that Vicki and Bennett have been living in fear of a bipedal creature called Koquillion - which Bennett claims is a native of the planet whose people have apparently killed the other members of the human expedition. He and Vicki are the only remaining members of the spaceship. They have only been spared so far as they have not left the safety the spaceship.

The Crashed Spaceship

A little while later, while looking around Koquillion attacks the time travellers by pushing Barbara over a cliff and temporarily trapping Ian and The Doctor. Vicki though finds Barbara injured and helps her back to the spaceship. While recovering Barbara realises that Vicki is evidently very lonely, having befriended an indigenous Sand Beast for company.

Then on hearing a disturbance outside Barbara mistakes the Sand Beast as a threat and kills it. Vicki is distraught and so when Ian and The Doctor return to the spaceship they find tempers are fraught between them.

Vicki Talking to the Rescue Ship

The Doctor tries to attract Bennett’s attention but is unable to get him to leave his room. The Doctor therefore decides to enter Bennett's room. Inside he finds things are not as they seem. The supposedly crippled Bennett is missing, and a tape recorder hides his absence.

The Doctor also finds a trap door in the floor of Bennett's room and follows it to a temple carved from rock where The Doctor deduces that Koquillion is in fact Bennett in disguise.

Bennett reveals he killed a crewmember on board the spaceship and was arrested, but the spaceship crashed before the crime could be radioed to Earth. It was he who killed the crash survivors, including Vicki's father, in order to conceal the murder he had committed on the spaceship. He has also killed the natives of Dido to cover his crime and has been using the Koquillion alias so that Vicki would back up his story.

Barbara and Vicki Helping Bennett

When The Doctor confronts Bennett about this he tries to kill The Doctor. However, two surviving native Didonians - whom Bennett thought he had completely wiped out - appear and force Bennett to fall to his death from a high rock ledge.

On discovering that Vicki's father was amongst the murdered crewmen, and that consequently she is now an orphan, The Doctor offers her a place aboard the TARDIS. The Doctor’s offers this invitation because Vicki also reminds him of his 'granddaughter', Susan who had recently left the TARDIS. With nothing left for her on Dido, Vicki grateful accepts his offer and so she is welcomed aboard the TARDIS.