Thunderbird 5 receives a call from Bob Williams, a young Australian boy who claims to have fallen from a cliff.
Thunderbird 1 is launched, but on reaching Bob's location in the
Northern Territory, pilot
Scott Tracy witnesses the boy being "rescued" by his brother Tony. Realising that the call was part of a children's game, Scott demands an explanation from the boy's father, a
weather station operator. Mr Williams explains that his sons idolise International Rescue and enjoy role-playing as them. Their mother is deceased, and Williams is too busy to keep a close eye on them, so he made them
walkie-talkies to keep them entertained. Taking pity on the boys, Scott flies them to
Tracy Island to for a guided tour of the base before they return home aboard
Thunderbird 2. The story is picked up on by the
Hood who realises the weather station to be a cover for a government project and he sets off to track down the Williamses and steal classified information. His suspicions are well founded: the station is actually Dunsley Tracker, a
spy satellite ground station where Mr Williams processes photographs of enemy military installations for Colonel Jameson of Satellite HQ. Tony and Bob are playing another game of "International Rescue". Disguised as a
surveyor, the Hood tricks Tony into hiding in an abandoned mine. After Bob ventures in to "rescue" Tony, the Hood detonates a bomb, triggering a cave-in that traps the brothers under a beam. With the boys out of the way, the Hood drives his off-road vehicle to the Williams homestead to steal the Dunsley Tracker surveillance. Almost succumbing to the Hood's
hypnotic powers, Williams, in the control room with the photographs, radios Satellite HQ for help. Jameson says that it will be hours before they can reach him, but Williams points out that International Rescue are faster. With the mine roof set to collapse, Tony and Bob call International Rescue. The Tracys ignore the boys, thinking that they are just playing again, realising the emergency only when Jameson calls on Williams' behalf. Scott blasts off in
Thunderbird 1 to help Williams while
Virgil and
Alan take
Thunderbird 2 to rescue the boys. The Hood uses a
cutting torch to burn through the control room door. He hypnotises Williams and seizes the photographs before Williams can destroy them. Landing nearby and proceeding on hoverbike, Scott confronts the Hood just as the villain is driving away. The ensuing chase ends when the Hood inadvertently goes over a cliff and is thrown out of his vehicle and into a lake. While Scott recovers the photographs from the crashed vehicle, Virgil and Alan reach the mine and extract Tony and Bob moments before the roof falls. The episode ends light-heartedly as the boys invite Scott to try their bedroom's "emergency exit", which deposits Scott on a
go-kart painted to resemble
Thunderbird 2. ==Regular voice cast==