On Jupiter's moon Europa Buddy and Ellie Pendergast are searching for extra terrestrial life. When they start drilling into the ice pressure from geysers causes the ice to crack and they fall into an underground ocean below a ten mile thick layer of ice. Alan and Gordon blast off in Thunderbird 3, with Thunderbird 4 modified with skis, powerful engines and a heat drill to penetrate the ice, which they lose due to strong underwater currents. They find the Pendergasts, who have taken shelter in their rover, but before they leave they detect a lifeform. As their escape ...
At Bay City, a town that was flooded due to global warming, the Mechanic, in a crab shaped submarine, is searching thought the ruins of the Creighton-Ward building for a safe containing the plans for Parkmoor Scrubs prison, so he can help the Hood to break out of it. As he smashes his way through some of the debris, it collides with a rental sub, which is being hired by the Sullivan family, coursing it to crash onto the seabed. While Gordon and Kayo work together to rescue the family, Lady Penelope and Parker try to get to the safe before the Mechanic gets to it first.
A cargo Zeppelin called Baross suffers damage and is on a collision course with a city. To make matters worse, two crew members are unable to abandon ship because one of the ship's loading claws has malfunctioned and has started attacking anything that moves in the cargo bay. Scott and Virgil must try to pull the ship up from its crash course, while Kayo takes on the claw and rescues the crew.
International Rescue come to assist when an atmospheric cleaning device goes haywire, trapping crew inside. While the Tracy brothers work on freeing the crew, Parker goes solo and squares off against a figure from his past.
While attending a gala with Lady Penelope, John must save the day when the Hood strikes and blocks all communications. Meanwhile, Gordon and Alan take John's place aboard the TB5, only to deal with a stubborn Eos.
Thunderbird 3 is called upon to save the life of the controller of the Moon cargo cargo station. Having to remain there to feed oxygen to the station, Thunderbird 2 is retro-fitted for space travel to deliver a new coolant core. But can Thunderbird 2 get back to earth in one piece?
A decaying mid-ocean oil rig will be shut down by Lady Penelope. The rig's manager sabotages the rig to stop her. As the rig begins to collapse, Penelope, Parker, Kayo and Virgil rush to save trapped workers and stop disaster from striking.