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: