A manned expedition led by Captain Black of Spectrum lands on Mars; investigating the planet surface in an exploration vehicle, the crew discover a futuristic alien city.

The Mysterons threaten the life of the Director General of the United Asian Republic and Spectrum swings into action to protect him as he prepares to board his private plane at London Airport.

The Mysterons threaten to destroy London and a truck carrying an atomic device goes missing in the city. The only clue to its whereabouts is the truck driver, found unconscious in the street

The Mysterons make their first mistake when Captain Black, revealed to have become a Mysteron agent, breaks into the Culver Atomic Centre and is exposed to radioactivity that will enable Spectrum to track him with directional geiger counters.

The Mysterons threaten to destroy key links in the Frost Line Outer Space Defence System.

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, Scarlet is dispatched to supervise security at the International Air Conference at Glen Garry Castle. Discovering a plot to gun down the delegates, he is captured and thrown in the castle dungeons...

The Mysterons' cryptic threat to ’kill time’ has the Spectrum personnel stumped until Magenta realises that their target is General Tiempo, the Commander of Western Region World Defence.

The Mysteron Gun and the Mysteron detector - two new anti-Mysteron devices - are unveiled at a top secret location.

Captain Scarlet resigns from Spectrum and deals arms to Captain Black! Can our hero really have joined the Mysterons?

As the Mysterons threaten to destroy the ‘Heart of New York’, Scarlet and Blue investigate the theft of Grade A Security documents from the Spectrum security vaults.

When the Lunar Controller announces the Moon's independence from Earth in the war of nerves with the Mysterons, Scarlet, Blue and Green journey to Lunarville 7 to investigate.

When the Mysterons threaten the life of the Supreme Commander of Earth Forces, Scarlet and Blue are assigned to escort him to SHEF HQ in New York to chair a briefing on the Unitron, an advanced unmanned tank.

Captain Scarlet goes undercover as a Fashion PR when models are endangered by the Mysterons.

In a plot to kill the spectrum Angels, the Mysterons get into a thrilling mid-air dogfight with Melody, Rhapsody and Harmony.

A major is killed, resurrected and controlled by the Mysterons with the dastardly aim of launching a Variable Geometry Rocket!

A dangerous lunar mission turns deadly for Scarlet, Blue and Lieutenant Green.

Astronomers at K14 Observatory are monitoring signals from a hidden satellite that has made a successful landing on the Martian moon Phobos.

Following a special discovery, Spectrum makes contact with the Mysterons in order to negotiate peace.

An oil rig inferno enables the Mysterons to gain control of an explosives expert for deadly and destructive purposes.

A world Air Force Major is killed and reconstructed by the Mysterons in order to destroy the world capital.

A flight carrying Scarlet, Blue and their ward Dr Conrad - a leading astrophysicist - is put in jeopardy by the Mysterons.

The Mysterons steal a deadly virus and threaten to drop it into the Los Angeles water supply.

Tritonium alloy mining operations at Hotspot Tower in the North Pole are threatened when a Mysteron agent cuts the power to vital heating elements.

A lorry carrying an atomic core reactor to the new Manicougan power complex falls into the hands of the Mysterons who intend to strike the Atlantic Seaboard of North America.

When the Mysterons threaten to destroy President Roberts within twelve hours, Scarlet is assigned as bodyguard to the sceptical President. But when 11 hours pass without incident, Scarlet begins to suspect that he is guarding the wrong target!

The Mysterons threaten to destroy the Triumvirate of Europe, the three most powerful men on Earth after the World President.

The Mysterons threaten to destroy the de-salination plant at Najama in the Andes, so Scarlet and Blue are sent to observe the plant from an Aztec temple that overlooks it.

The finger of blame points at Captain Scarlet after a series of hovercraft accidents.

When the Mysterons threaten to destroy the World Navy Complex at Atlantica, Blue and Ochre fly a V17 Air Force bomber to destroy a wreck that has been sighted drifting towards the base.

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

A drugged Captain Blue awakes to find himself under interrogation on Cloudbase. He has apparently been missing for three months and must now prove his identity to Intelligence agent Colgan by revealing Spectrum's top secret cypher codes.