 Set in the 2060s, the series follows the exploits of International Rescue, a secret organisation that uses highly-developed rescue machines to save human life.The main characters are ex-astronaut Jeff Tracy, the founder of International Rescue, and his five adult sons, who pilot the organisation's primary vehicles – the "Thunderbird" machines.In "Pit of Peril", International Rescue rush to save the crew of an experimental US Army walking vehicle that has fallen into an abandoned military dump.