A manhunt begins for former Spectrum agent Captain Black after a failed break in at a nuclear power plant, where he is accidentally exposed to radiation and becomes detectable for 48 hours.

The Mysterons threaten to kill Colonel White and after their initial attempt fails, White elects to leave Cloudbase so as not to place the other Spectrum agents in jeopardy.

Following the latest Mysteron threat, Captain Scarlet is dispatched to supervise security at the International Air Conference at Glen Garry Castle in Scotland.

Spectrum and the World President attend a secret conference on an African game reserve to demonstrate two new anti-Mysteron gadgets, a Mysteron Detector and a Mysteron Gun but the aliens announce they intend to sabotage the event.

Destiny and Symphony Angels go undercover as models when the Mysterons target fashion designer Andre Verdain, who is also the secret controller of the European Area Intelligence Service.

Mysteron agent Judith Chapman, steals a phial of deadly K14 virus - enough to kill ten million people - from Biological Research Station with the intent of poisoning a unknown cities water supply.

When the Mysterons threaten to destroy President Roberts within twelve hours, Captain Scarlet is assigned to guard the skeptical President of the United States.

Captain Scarlet and the rest of Spectrum are in a desperate race against time to defeat the Mysteron's latest threat, the total destruction of the massive desalination plant at Najama, high in the Andes Mountains.

Spectrum personnel inexplicably take leave of their senses, due to drinking some champagne drugged by the Mysterons, who have threaten to destroy the World Navy Complex at Atlantica.

After the Mysterons threaten Spectrum's Cloudbase headquarters, a large fast-moving trace appears on the radar.

Captain Blue disappears from a restaurant. He awakes to find it is 3 months later and Spectrum Security want to know where he has been, and if he is even the real Captain Blue.