Two scientists are killed and reconstructed by the Mysterons as assassins infected with a disease that can kill with just one touch. Captain Scarlet and Captain Blue are into a hunt against the clock to find them but unknown to the 2 Spectrum agents the Mysterons target is the president of The United States.

When members of the world Security Council start to commit suicide Colonel White sends Captain Scarlet & Captain Blue to invistigate. Captain Blue checks out one of council members computers and reads an email that hypnotizes him, he uploads the computer to Lieutenant Green. Blue drives of road but Scarlet saves him Blue goes into a coma. Scarlet takes him back to skybase. But the virus has spread to Skybase's computer systems.

Spectrum detects a massive unidentified spaceship leaving Mars which soon lands in the Australian Outback. Colonel White sends Captain Scarlet, Captain Blue, Captain Ochre and Captain Grey to investigate the spaceship. They board the ship and find out that the renegade Mysteron faction has sent the ship which has the ability to time travel. Scarlet is told that he has a chance to go back in time and stop the war from happening.

In the frozen wastes of Russia, Captain Black steals a prototype organic limpet mine from the Russian Navy Technology Division and ends up being pursued by Captain Scarlet in a Spectrum Rhino. After a brief chase and a fight in the snow, Scarlet and Black end up trapped in the Rhino under frozen ice. With no way to escape, can Scarlet and Black work together to get free?

Doctor Phil Bogart, the designer of the devastating Thunder Pulse compression bomb, which is used as a sonic displacement weapon, is killed and reconstructed by the Mysterons. After stealing his invention and going into hiding, Spectrum turns to his twin brother, Frank Bogart, a convicted criminal who has a telepathic link with his brother.

Captain Scarlet, Colonel White and Lieutenant Green are aboard Proteus, a new state of the art stealth ship on it's maiden voyge. The Mysterons soon take over the ship and use the ships repair bots as weapons agains Scarlet, Green and White. Meanwhile the Mysterons plan to use Proteus to shoot a Chinese ship with the President of the Chinese People’s Republic on board and start a world war between America & China.

Vulcan Industries sends a 3 man crew to Mars to fix their mining post Syrtis Major even though its a breach of the Martian Exclusion Directive. Spectrum finds out and Colonel White sends Captain Scarlet, Captain Blue, Captain Ocher, Doctor Gold, Destiny Angel and Griggs, Vulcan Industries chief engineer, on a rescue mission.

After being shot down on a deserted tropical island, Angels Destiny, Harmony and Melody feel like they are in Paradise, until the Mysterons send replicas of modern-day pirates to pry the secret location of the World Summit from them.

In the small town of Ragnarok in Alaska, which the Mysterons have destroyed and replicated, Scarlet and Blue are captured and forced to help mine for an ancient meteorite bearing a spore that can kill all life on Earth..

Spectrum recives word that a nerve agent is being bought by Mysteron agents in New York. Captain Scarlet manges to get to the nerve agent but finds out the whole thing was a trick. Scarlet talks to his informant who tells him the real target is 'Tranquility’ a lunar biosphere holiday camp on the moon. Unknown to Scarlet the informant is a Mysteron replicant and the whole thing is a trap set up by Captain Black. Aired:

Captain Scarlet is guarding a particle collider at the Laroux Foundation in Louisiana, 2 Mysteron Replicants try to break in but Scarlet takes care of them. In the firefight a container tank is hit and releases a gas type substance which the Mysterons take over. An exact copy of Captain Scarlet walks through the gas and shoots the real Captain Scarlet dead. The fake Scarlet disposes of the real Scarlet and makes his way back to Skybase where he can turn himself into whoever he touches and sets out to kill Colonel White and destroy Skybase. Aired:

Captain Black claims he is free of the Mysterons' control and suggests Scarlet return with him to Mars in a daring plan to destroy the Mysteron complex. Can Black really can be trusted – or is Scarlet being led into a final, lethal trap?

After the Mysterons take over a Phoenix policeman named Rimmer and use him to steal a canister of deadly alien spores brought back by a space probe from Ganymede, Captain Scarlet and Captain Blue are ordered to give chase. But they are thrown off their trail when the Mysterons take over a biker named Brock and use him to carry out the plot instead. Meanwhile, Captain Ochre's Raid Bike is stolen by another biker named Colt.