Fathom Harvill, [Raquel Welch], a skydiver, is in Spain with a U.S. parachute team. She accepts a lift from [Richard Briers], who plays Flight Lt. Timothy Webb, and is taken to meet [Ronald Fraser] as [Douglas Campbell], who claims to be a British agent working for NATO and asks for her help locating a triggering mechanism for a nuclear weapon that has vanished in the Mediterranean. He explains the device is hidden inside an ancient Chinese figurine known as the Fire Dragon. This dangerous, globe-spanning chase hinges on trust and deception.
Following Campbell's plan, Fathom skydives into the villa of [Anthony Franciosa] as Peter Merriwether, a private investigator who is also searching for the figurine, and she meets his Chinese assistant, Jo-May Soon [Greta Chi]. There, she discovers a dead body and is caught by Merriwether, who accuses her of murder. Despite the tension, Fathom manages to convince Merriwether of her innocence, and the two begin to piece together the tangled web around the missing weapon and the coveted Dragon. The atmosphere thickens with suspicion and shifting loyalties.
Merriwether reveals a grim truth: the NATO briefing was a ruse, the Fire Dragon was stolen from a Far East museum by a Korean War deserter, and Campbell himself is the deserter. The chase broadens as Serapkin, a wealthy Armenian private collector, enters the race, desirous of adding the Fire Dragon to his own collection. [Clive Revill] brings Serapkin vividly to life as the pursuit heats up across oceans, borders, and backroom deals. A game of cat and mouse escalates quickly.
After a knife attack and a harpoon strike, Fathom finally discovers the Fire Dragon tucked away in her makeup case. Campbell, once again trying to steer the story, positions himself as the trustworthy ally while Merriwether is cast as the deserter in the escalating showdown. Fathom boards a plane with him and Timothy, but the plan quickly spirals into danger as they attempt to throw her from the aircraft with a defective parachute. Merriwether corners them in another plane, and a dramatic aerial duel erupts as both pilots jostle to force the other down into the sea. In the heat of the confrontation, Merriwether shoots Campbell dead, shifting the balance of power once more.
When Timothy draws a weapon, Fathom fights for control, and Timothy falls from the plane. With the balance finally tipping in his favor, Merriwether leverages Fathom’s passport to secure her cooperation. He convinces her to pass the Fire Dragon down to Jo-May Soon, so it can be returned to China, and to meet him again later in a bar. The chase resolves not with a simple victory but with a fragile agreement born out of risk, wit, and a willingness to gamble with nearly everything at stake.
