A Mysteron sniper performs an unsuccessful attempt on the forces' new target: The Director General of the United Asian Republic, with Captain Grey arriving in the nick of time, and succeeding in disposing of the eavesdropping gunman. From then on, all personnel from Cloudbase and Spectrum H.Q. – London, along with the recovering Captain Scarlet, and his original partner Captain Blue, are dispatched to protect the Director General at all costs, whom has made arrangements to return to his home country. But the Spectrum officers are completely unaware of the inbound Mysteron-reconstructed civilian Stratojet airliner, the enemies' tool to fix and complete their assassination upon the important international foreign figure.