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.

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?