The plane is bound for bound for Boca Grande, somewhere in South America, making a pick-up stop in Central America.

Passengers: Jud Ellis escorting his fiancé Louise Melhorn; repentant political assassin Vasquel is being transported back to the proper authorities by detective Crimp; mobster Pete Bostwick accompanies a little boy named Tommy whose father may have been murdered by Bostwick himself; elderly couple Professor. and Mrs. Springer are apparently on vacation; and jilted blonde bombshell Rena, on her way to a South American casino, vies for Ellis' attention.

After the final takeoff, the plane flies through a rough storm and is dangerously jostled about. A portable gas tank is loosened from its mooring, which then blows out one of the fuselage doors, killing one of the flight attendants as she is thrown out.

The crew is then forced to make an emergency landing in the jungle, aircraft intact. Crimp tries to take charge of the group, but the captain stops him.

Momentarily, Ellis becomes psychologically unhinged, and tries to force himself upon Louise, but co-pilot Brooks steps in to dissuade him.

Late at night, Crimp renders Bostwick temporarily unconscious, steals the guns he was guarding, then flees into the jungle.

Later, the aircraft is repaired, but soon after searching and finding an errant Tommy, Bostwick and Rena discover Crimp’s headless body. Soon, local head hunters shoot Bostwick dead by poison dart.

The crew and passengers decide the best escape strategy; since there is only one good engine to help the plane fly over the mountains, the human cargo will have to be exceptionally light, so some will have to stay behind. With gun in hand, Vasquel forcibly takes charge of the matter, and chooses those that will be able to return to civilization; Ellis tries to stop him and is shot dead. The plane manages to take off, dropping off a cliff and then narrowly clearing the mountains.

The elderly Springer couple choose to stay behind, facing a horrible death from the head hunters. With only two bullets left in his gun, Vasquel shoots the Springer couple and prays for forgiveness as he waits for his own death.