An undercover operation in Honolulu ends in tragedy when an agent carrying a map that could reveal secret uranium deposits in the South Pacific is gunned down, triggering a globe-trotting chase filled with danger and deception.
In Los Angeles, Hobe Carrington tries to turn down Countess Maria de Fresca's request to hire him as a pilot for a flight to Death Valley. She tempts him with a dinner date, and he relents. Before they can depart, Carrington runs into his former superior in the armed forces, Bob Donovan, now an FBI agent, who warns him to keep an eye out for the missing map.
The Countess and her party—Catherine Forrest, James Van Bush, Claude Forrest, and mining engineer Gerald Porter—are told they might need oxygen masks mid-flight as they overfly a brewing storm. In a tense moment, [Catherine Forrest] switches seats with the Countess, but her oxygen mask becomes disconnected, forcing Carrington to dive in to save her life. The Countess later confides that someone may have actually intended to kill her.
Donovan beats the flight to Death Valley and explains that his passengers may be international racketeers who likely have the map. The group encounters mining engineer Tom Walker, and while they orbit the mystery of the map, Walker tries to buy it back from Claude Forrest. He also bribes the Countess for a secret letter about Claude. By a twist of fate, Carrington’s ex-wife, Irene Allison, who is in Death Valley, learns that the Countess is really Dolly Lorraine, an ambitious actress with a past Irene once worked with in a magic show. The revelation adds another layer to the motives swirling around the coveted map.
Back on the ground, Carrington rescues [Catherine Forrest] from James Van Bush by tossing the bothersome suitor into a swimming pool. He also notices Catherine wears a distinctive gold ring from Japan that Claude gave her, a clue that ties the actors together. Throughout the evening, the secret letter is stolen multiple times—the fifth time from [Tom Walker], who is murdered in the confusion.
Briefly detained for questioning about the murder, the group decides to fly to Las Vegas after failing to sell the map. Irene, who lives in Las Vegas and hopes to go home, asks to accompany them. In Las Vegas, Claude tries to sell the map to Joseph Herman Ruehl at Ruehl’s horse ranch. Donovan explains that the secret letter reveals Claude’s treasonous ties with the Japanese to locate uranium, and the twist reveals that the so-called map is actually Catherine’s ring.
Irene Allison, a licensed pilot, borrows Carrington’s aircraft, but the plane is sabotaged and she dies in a crash. The tension peaks as Gerald Porter waits to seize the map; after a struggle, he is killed by Carrington’s swift intervention at Ruehl’s ranch. The Countess Dolly Lorraine and Ruehl are detained by Donovan before they can leave town. Carrington confronts James Van Bush again, exposing him as a gold digger after Catherine’s wealth and shoving him back into the pool to cool off.
With Claude’s fate settled, the remaining players converge on the ranch, where Porter’s last demand—Catherine’s ring—nearly spells disaster. Donovan arrives in time to shoot Porter, saving Carrington and Catherine from harm. In the end, the couple—Catherine Forrest and Hobe Carrington—prepare to fly to Las Vegas to be married, with Bob Donovan standing as the best man.
