The voyages of the Star Ship Enterprise across man's final frontier - space! Its mission: to explore strange new worlds, to seek out new life and civilisations, to go boldly where no man has gone before.

There isn't more loyal, conscientious officer in the Star fleet than Mr. Spock, yet the message he gives to Captain Kirk ordering him to Starbase 11 proves to be false. More startling still, when the U.S.S. Enterprise abandons her incredulous captain and sets illegal course for the forbidden Talos IV, there is another captain aboard and the loyal Spock is in control!