Three weeks after losing contact with Elysium Base on Mars, a team consisting of Captains Scarlet and Blue, Destiny and Harmony Angels, and Doctor Gold are sent to find out what happened to the crew. On arrival, they realise it is a Mysteron trap and that they are under attack from an titanium armour-plated research robot named Remote Acquisition Technology (RAT) which carries lasers and a diamond-tipped saw. Under Mysteron control, the RAT has become the ultimate killing machine.

Joe tries to find out whether the crash of a prototype spaceplane was an accident or sabotage.

Koenig convinces Helena to doubt the credibility of the visitors and treat Maya the same way he was treated. Maya can confirm Koenig's perception of aliens and after treating nearly everyone, Koenig, Maya and Tony work to stop the aliens, whose real intent is to detonate nuclear fuel to provide their sustenance.

Koenig seems to go berserk while flying an Eagle; as he is in Medical Center unconscious, a Superswift appears, lands and its crew is revealed as a team of people from Earth come to take the Alphans home. When Koenig seems to recover after some wave therapy applied to his brain, he does not see the old friends and acquaintances everyone else sees, nor a Superswift; Koenig sees hideous telepathic aliens and an alien spacecraft.

Matic builds a time machine that whisks Zodiac, Venus and Commander Zero back to the Wild West of 1875, where Zodiac becomes a sheriff and Venus and Zero execute a bank robbery.

Mitch gets a girlfriend when engine trouble forces Supercar down in the jungle.

An actress who is the daughter of a Hungarian exile hires the Protectors to help arrange a secret funeral for her father so that he can be buried on home soil.

An undersea civilisation creates a weapon capable of obliterating the West Coast of America.

Threatening to destroy the "Place of the Angels", the Mysterons engineer the theft of a lethal virus from a research centre.

The passenger aircraft Skythrust, conceived by Brains using the alias Hiram K. Hackenbacker, falls into the hands of fashion criminals who hi-jack the plane to steal a new French design from the renowned François Lemaire.