 In 2067, at the conclusion of an investigation into the loss of Zero-X, the Inquiry Board of the Space Exploration Center reaches a verdict of sabotage. In the meantime, a second Mars mission has been planned. Days before the launch of the new Zero-X, International Rescue agrees to a request to organise security in view of the possibility of another sabotage threat. Jeff Tracy dispatches Scott to Glenn Field in Thunderbird 1, while Virgil in Thunderbird 2 and Alan in Thunderbird 3 are assigned to escort Zero-X as it leaves the atmosphere. Posing as a reporter at the pre-launch press conference, Lady Penelope ensures that Travers and the other four crewmembers are delivered St. Christopher brooches. Ostensibly for luck, these are in fact homing devices (a plot device previously used in the episode "The Duchess Assignment"). The next day, a search for Dr Grant's brooch checks negative. Scott unmasks the man waiting for lift-off on board Zero-X as the Hood in another of his disguises. The saboteur flees Glenn Field in a car, which Penelope and Parker pursue in FAB1. The Hood transfers to a speedboat, and then a helicopter piloted by an accomplice; Parker shoots the aircraft down with the Rolls-Royce's built-in machine gun and the Hood is seemingly killed. Meanwhile, the real Grant is returned to Zero-X and the spacecraft launches without further incident.
