 The first episode begins with a group of human astronauts destroying the Mysteron city on Mars due to a misunderstanding, only for the aliens to reconstruct their settlement.The Mysterons then declare a "" on humanity, intending to destroy high-profile targets one after the other.On Earth, Captain Scarlet and fellow Spectrum officer Captain Brown are killed in a road accident and replaced with Mysteron doubles programmed to carry out the aliens' first threat – the assassination of the World President.