The Fireflash, on its maiden flight from London to Tokyo, is sabotaged by the Hood, a criminal who has learned of the formation of International Rescue, and is unable to land. The Hood's attack is intended to draw out International Rescue so he can record secrets of its machinery for sale to the highest bidder, an attempt thwarted by the intervention of the organization's London Agent.

A 500-ton U.S. Army walker, Sidewinder, falls into a pit during testing and International Rescue are called to save the crew trapped inside.

While returning from a mission, Thunderbird 2 is seriously damaged when it comes under attack from a new, high-speed U.S. Navy strike vessel, the U.S.N. Sentinel. After an operation to move the Empire State Building disastrously ends in the tower's complete collapse, Jeff asks that Thunderbird 4 be transported onboard the same ship to the mouth of an underground river to reach a reporter and his cameraman who are trapped beneath the wreckage.

A series of unexplained Fireflash airliner disappearances sees Thunderbird 4 being called to rescue a crew stranded on the ocean floor. International Rescue then volunteer its services in helping to diagnose the cause of the mechanical fault.

During the installation of a new, airtight security vault at the Bank of England, one of the employees is accidentally locked inside, and International Rescue must come to his rescue before the air is extracted.

The Hood arranges for a mishap with explosives during a film shoot, leaving two of the actors sealed inside a cave. When International Rescue arrive the ensuing rescue is surreptitiously recorded by the Hood, and when the Tracys realize they've been set up a tense chase through the nearby desert ensues.