When a radio station relay and communications satellite is recreated by the Mysterons and its course altered towards Cloudbase, Colonel White orders the fatal missile to be destroyed before it collides with the aerial base.

Infuriated at his superior for dis-regarding the non-existent, but beknown to Scarlet, lives of the men on-board the satellite, he declines White's proposition to be temporary commander-in-chief of Cloudbase, and therefore, the offer is handed to the honoured Captain Blue.

Leaving for a surreptitious destination, which only White has exposed to Lieutenant Green, and with harsh instructions not to publish it to anyone at all, he arrives on-board the USS Panther II submarine, with the alias Robert Snow, where shortly after one of the ensign officers is, with intent, murdered and reconstructed by the Mysterons in their newest play of vengeance to kill Colonel White.

Spectrum Intelligence impart Captain Scarlet with a ""special assignment"" which is to consciously loose inadequately at a casino, and to place himself on their debt owners list for 5,000 credits. When this is reported to Spectrum Headquarters, Colonel White fires Scarlet on the spot, for improper use of the organisations' code of conduct, and his occupation taken away from him.

Living in a inexpensive, shabby hotel room temporarily, a pair of Mysteron agents, posing as sought after gangsters, formulate a deal with the now Paul Metcalfe, with his I.O.U. for 5,000 credits, in return for a Spectrum Pursuit Vehicle, which will be utilized to brake into the Nevada Nuclear City Complex, with an atomic incendiary device, which will obliterate the whole of North America.

The commanding controller of Lunarville 7, a small colonised base on the opposite side of where the main Mysteron complex is located on Mars, announces that he has made direct contact with the force, and agreed to a undisturbed, and peaceful settlement, and to finally end the war of nerves, but this is a trick by the Mysterons, as the controller and his personnel aid are reconstructed agents, and have Captain Scarlet, Captain Blue and Lieutenant Green trapped on the compound when they are sent to investigate how he managed to make a deal with the Mysterons.

When suspecting that the controller and his right-hand man could be Mysteron agents, they non-attentively leave Lunarville 7, and travel to the Humboldt Sea, the far side of the Moon, where an enormous, and potentially powerful Mysteron complex is being developed and built in Crater Number 101.

A modern generation kind of tank, the Unitron – a deadly computer-assisted vehicle, is seized by the Mysterons to destroy the Supreme Commander of the Earth Forces, when he is escorted by Captain Blue to the tanks' testing range field in the Sahara desert.

Two of the Commander's highest-ranking officers, Colonel Storm and Major Brooks, while en route to the SHEF headquarters, are killed in an explosive collision in a mountain-integrated tunnel, involving their car and a gasoline tanker truck, and consequently revived back to life with Mysteronised bodies.

Both men are used as composers to complete the Mysteron's threat, with Major Brooks' attempt becoming unsuccessful, but Colonel Storm's turning into a life-threatening situation when accompanying the Supreme Commander to Point 783, the acting command post where the two test co-ordinators are carrying out final tests with the Unitron, but little do they know that the Mysterons have programmed the mighty formidable weapon to seek and de

Captains Scarlet and Blue travel to the Himalayas to supervise and administrate Spectrum's new phase to monitor signals from a space satellite that has been launched into the orbit surrounding Mars, and to snap-shot high resolution detailed pictures of the planet, which will be relayed and received by the large mountain satellite station that the probe was launched from.

The second satellite, with the first acting as a decoy, successfully lands on Mars, and sets to have Spectrum successfully completing the code-named ""Project Sword"" operation, but the whole carefully-planned out arrangement is placed under threat when one of the participating technicians ostensibly falls dead and is brought back to life by the Mysterons, with one instruction: to sabotage the observatory and to interrupt the satellites' transmission, before Earth comes to learn every single detail about the force, and prevent them from continuing the war of nerves and retaliation against the planet.

Spectrum are involved with the safe, quiet transportation of escorting the world's leading astrophysicist, Doctor Congrad, to a Switzerland-located conference with the World President at Lake Toma.

After boarding their mysteriously-empty flight, which could possibly be due to it being the ""slack"" season, with planes flying usually 3/4 empty, but with no hostesses around, Captains Scarlet and Blue become suspicious, and realise that they are trapped on-board the airliner, along with two tagging-along, & over-confident news-reporters, when learning there isn't any pilots flying the machine, immediately suspecting the Mysterons are controlling it.

But that's not the least of their worries when the plane starts to descend rapidly, and its nose pointing straight in the direction of the French Alps.