When their ship crashes beneath the surface of a newly formed planet, the Minyan survivors discover what they have been searching for. But their arrival is not welcomed.
The Doctor and Leela attempt to penetrate the Citadel of the Seers to rescue Idas's father who has been sentenced to death.
Death rays seem to be coming from a Scottish research center.
Simon meets several people who are after 3 lost Da Vinci's.