Ark craft Pisces has been searching for habitable planets for ten years - their time. On the Ark 409 years have passed, proving Einstein correct. But there are penalties to suffer for travelling that fast.
With Devon seriously injured, Rachel's call for help reaches the Astro-medic ship. At the same time an alien spacecraft is also appealing for assistance. The two main doctors - father and son - are at loggerheads: who do they try to save?
Searching for a way to repair the Ark, Devon, Rachel and Garth arrive at the Omicron biosphere, which may have some ancient technical books. All the women died long ago, and Rachel is mistaken for the goddess the men worship.
Escaping from the savage descendants of the security crew, the three waken a technician from cryosleep to help them repair the ship and prevent the coming collision. But he is dying, and the wrong sort of specialist.
The angry, embittered Dr Richards tries to escape the Ark with his daughter after triggering the ship's self-destruct mechanism. His capsule fails to launch, and the self-destruct can't be overridden. But there is a very dangerous fix.
A mysterious, bewitching art gallery proves to be the creation of Magnus, said to be the greatest mind in the universe. But who - or what - is he, and how can he help correct the course deviation that threatens the Ark with destruction?
A year ago Oro of planet Exar crashed into the Ark, and with the help of Idona has been cannibalising Ark components to make repairs to his scoutship. Oro plans to take Idona back home with him - but then she meets, and falls for, Garth.
Devon tours a huge spaceship, the ark, to discover who built it and where it's taking them. In Each episode Devon meets someone and finds out a little bit more about it.
The trio blunder into a sealed, highly industrialised biosphere, where outcasts die in the toxic air outside a sealed city ruled by a paranoid, self-deceiving leader who is preparing for war - if he could find a way out.
Oro returns, offering to repair the Ark's faulty systems and fly them all to settle on Exar, which he claims is much like earth. Devon discovers he's lying, but can only prove it in a debate in which the loser will be killed.