A Yank in Indo-China

In war-torn Indo-China, American geologist Professor William Marlow is taken prisoner by Communist Chinese while surveying areas for rubber development. Soon after, American pilot Clint Marshall and co-pilot Swede Philips are summoned to Hanoi by the American consul, Mr. Kingston. Clint and Swede run a cargo airline ferrying food to the French and Vietnamese forces battling the Chinese, prompting Kingston to request that the men search for Marlow by air and report any unusual activity. When Clint and Swede return to their home base at Ling Chai that afternoon, Chinese soldiers led by Capt. Sung Minh take over the airport and demand that the pilots use their plane and friendly relations with the French to fly through the French blockade to retrieve ammunition for them. When Swede adamantly refuses, he is shot and killed by Sung. In order to save the others at the airport, including ground crewman Mulvaney, Swede's pregnant wife Ellen and company assistant Cleo, Clint agrees to Sung's request. Several Communist Chinese guards accompany Clint and Mulvaney on their flight to pick up the ammunition and secret orders for Sung to give to Gen. Wang, known as the "Red Butcher." On their return flight, Clint and Mulvaney inhale oxygen as they pilot the craft to a high, oxygen-thin atmosphere that knocks the guards out. While the guards remain unconscious, Clint rigs the ammunition to blow up when unloaded and steals the secret orders. Back at the airport, the ammunition explosion diverts the Chinese allowing Clint, Mulvaney, Cleo and a distraught Ellen to flee into the jungle in their jeep until the jeep's tire becomes flat. Forced to proceed on foot in the hot jungle, the group is surprised by the appearance of Jake, a young native orphan who haunts the air base and is friends with Mulvaney. Despite Ellen's fatigue and distress, Jake guides the group to a village where the peasants offer them native clothing and food. When Sung and his pursuing forces threaten the village, Clint sends Jake off alone with the secret orders before he and the others surrender. Clint's refusal to turn over the plans provokes Sung to massacre the peasants and burn down the village. The group is then taken to Wang's secret stronghold and placed in an underground jail along with Marlow, who has been tortured by the Chinese on suspicion of espionage. Clint and Mulvaney discover Marlow's generator in the cell and set it up to electrify the prison bars, which kills their guard and allows the group to escape. While fleeing through the jungle with Marlow, who has become traumatized by his torture, Clint and the others are rejoined by Jake, who had followed them upon their capture and lingered in hopes of providing help. Pursued by Sung's men, the group is placed in additional danger when Ellen goes into labor. With Cleo's help, Ellen safely gives birth, but the baby's cries draw Sung's guard. Clint and Mulvaney overpower the soldiers and, having discovered a military motorboat anchored on the river nearby, the group attempts to make their escape before the arrival of Sung and the rest of his forces. While Clint and Jake struggle to start the motor, Mulvaney finds several grenades on board the boat and fends off the attack by Sung. As Clint gets the engine started, however, Jake is killed by gunfire. The others return safely to Hanoi, where Kingston and a recovered Marlow express their gratitude. Kingston then asks for assistance in finding Wang's headquarters. Intent on avenging young Jake's death, Mulvaney and Clint lead a Vietnamese and French military raid on the jungle hideout, which successfully destroys Wang and his forces.