General Yang, Akim Tamiroff, a warlord who controls one Chinese province, dreams of sweeping across the land to corner the silk, rice, and opium markets. His ambitions meet stern resistance from Mr. Wu, a calculating opponent who believes Yang’s army is too thin and too prone to desertion to hold a country-wide grip. To counter Yang, Wu recruits O'Hara, Gary Cooper, a tough, world-weary soldier of fortune, to travel to Shanghai and strike a weapons deal with a gunrunner in Brighton. The money funding this dangerous venture is said to be carried in a belt, a stash built on the backs of peasants crushed by Yang’s regime. Into this maelstrom drift the Perrie family—Peter Perrie, Porter Hall a dying man looking to secure a future for his daughter, and Judy Perrie, Madeleine Carroll who reluctantly agrees to be part of the plan so she can see America.
The scheme centers on distracting O'Hara while Yang’s cross-border push unfolds, and Judy accompanies her father on a journey that will play out on a train and beyond. Leach, J.M. Kerrigan, a schemer hungry for a cut, lurks in the background, trying to bend events to his own advantage as the money’s whereabouts become increasingly critical. Peter, driven by a mix of desperation and love, hides the funds in the lining of his suitcase, insisting that Judy proceed despite her growing misgivings about the plan.
O'Hara manages to escape Yang’s initial capture and makes his way toward the house where Wu awaits. Yet Peter’s attempt to safeguard the hoard—by firing a shot at Wu and thwarting the moment—ends with O'Hara gaining the upper hand and Peter meeting a grim fate at his enemies’ hands. Yang arrives with his captive trio—Judy, O'Hara, and Wu—on a boat, intent on extracting the money before the operation can unravel.
The tension tightens as Leach’s opportunism is crushed when Yang’s men shoot him, and Judy is pressed to a heart-wrenching choice: she is forced to consider telling Yang where the money lies, a move that would endanger everyone else. In a sudden turn of fate, Brighton, William Frawley and a man slipping into a stupor while seeking a drink, stumbles into Yang’s soldiers and inadvertently alters the balance of power. He awakens to confront the danger and, in the chaos, nearly brings about Yang’s downfall by mortally wounding the general with a knife.
O'Hara pleads for mercy, arguing that sparing the trio would preserve a story of loyalty and honor for the world to see. Yang, testing a grim sense of honor, orders his own men to turn on one another before he dies, a symbolic collapse of power as the dawn light spills over the scene. In the end, Judy and O'Hara share a quiet, hopeful embrace as the sun rises, the peril behind them but the memory of the night lingering in the air.
