Scarlet and Destiny are undergoing interrogation resistance exercises at the Spectrum Training Base in Scotland when the base commander, Astrid Winters, is killed in a car crash engineered by the Mysterons. Resurrected as a Mysteron replicant, Winters returns to the base with the stunning revelation that she represents a faction of the Mysteron Consciousness which does not believe in the war of nerves. Offering to detail how Spectrum can defeat the Mysterons, Winters insists that she can only deliver the information to Colonel White in person, but as proof of good faith she exposes the Mysterons' plans to wipe out Earth's scientific elite in a single strike on the World Science Congress!

• Gerry Anderson

• Emma Tate
• Mike Hayley
• Wayne Forester