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.

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.