When two belligerent Dominators and their robotic servant Quarks land on the peaceful planet Dulkis planning to drop a radioactive seed into the planet's core to refuel their spaceship, the Second Doctor, Jamie and Zoe must attempt to inspire the pacifist Dulcians to resist.
Patrick Troughton
as The Doctor
Frazer Hines
as Jamie McCrimmon
Wendy Padbury
as Zoe Heriot
Ronald Allen
as Rago
Kenneth Ives
as Toba
Arthur Cox
as Cully
Felicity Gibson
as Kando
Giles Block
as Teel
Johnson Bayly
as Educator Balan
Walter Fitzgerald
as Director Senex
Alan Gerrard
as Bovem
Brian Cant
as Chairman Tensa
