Returning home from an aborted mission, Thunderbird 1 is gunned down by a trio of mysterious fighters manned by a group of people called the Zombites. Scott Tracy, badly wounded in the attack, is saved by a pair of passing explorers named Wilson and Lindsay. The explorers radio for help, and Thunderbird 2 arrives shortly thereafter. Discussing the situation, International Rescue discover the two explorers are seeking the Lost Pyramid of Khamandides, a fabled structure filled with unimaginable wealth. Wishing them luck, the Thunderbirds return home.
However, luck is not with the explorers. Their trailer, containing food, water, gas and their radio, falls down a dune and explodes. Without supplies and with their radio badly damaged, the two desperately attempt to reach safety. They find... the Lost Pyramid of Khamandides, filled with gold and a still working fountain. But unfortunatley, it turns out to be the hideout of the Zombites.
- Adventure Archaeologist: Wilson and Lindsay, the two explorers.
- Big Damn Villains: The Zombites save Scott from a crazed, trigger-happy Lindsay.
- Con Lang: The Zombites speak in their own non-English language.
- Deadly Gas: what the Zombites use to fuel their fighters. It becomes their downfall later on.
- Drives Like Crazy: Wilson, despite Lindsay's warnings to respect the sand. His reckless driving results in the accident in which they lose their trailer.
- Idiot Ball / Jerkass Ball: Lindsay when under influence of the Gold Fever.
- Lost Forever: at the end of the episode, thee Lost Pyramid of Khamandides explodes. One of the explorers remarks that it is "lost forever".
- Futuristic Pyramid: zigzagged; the Pyramid itself is thousands of years old, but the Zombites have heavily modified it when they made it their headquarters, like installing missle launchers in the sides.
- Gold Fever: When Scott arrves in the pyramid, Lindsay, instead of accepting rescue, instead engages Scott in a gun fight since he honestly thinks Scott wants to steal the treasure he and Wilson just found. It could be partly because of the water he drank from the fountain earlier.