Judith Denning Carole Lombard, a young widow, earns her living as a cafe singer in colonial-era Malaysia. The colonial authorities threaten her with deportation for indecency, but she has nowhere else to go. Judith has a chance meeting with wealthy but lonely rubber plantation owner Horace H. Prin Charles Laughton, who she agrees to marry in order to escape deportation.
Judith travels inland to Prin's plantation, where she discovers the Malay workers are poorly treated and ill-fed, while the white foremen are fugitives coerced into working far from the reach of the law. Prin imposes a tyrant’s rule, exercising capricious authority and a cruel sense of humor that unsettles everyone around him. One of the foremen, Hambly James Bell, attempts to escape downriver, but is killed by Malay tribesmen hired by Prin, a fate that has befallen other escapees. Judith quickly grows to resent the regime she has joined and the fragile illusion of safety it offers.
She finds a glimmer of hope in David von Elst Kent Taylor, a deserter from the British Army who has been coerced into working on Prin’s plantation. They fall in love and secretly plan to run away together, but their resolve is continually tested as Prin’s control tightens. David is eventually reassigned upriver, tearing at their chances and pushing them toward a dangerous decision that could seal their fate.
Prin’s domination is challenged when a new challenger arrives: Ballister Charles Bickford, a strong-willed American hired to replace Hambly. Ballister openly defies Prin and begins making unwanted advances toward Judith, complicating the lovers’ plan and introducing a tense new dynamic into the oppressive world of the plantation.
A spark of conflict ignites when Malay chieftains visit Prin to negotiate a trade deal, but the tyrant’s arrogance infuriates them. He insults them, and the Malays declare war. The upriver posts become the first to be attacked, and David manages a perilous escape through the jungle back to Prin’s headquarters. Judith and David seize a moment to flee downriver when Ballister foils Prin’s sabotage attempts on their boat, leaving the plantation vulnerable and exposed.
Prin surveys his abandoned domain with a brittle confidence, convinced he can defend what remains. Yet his hidden defenses have already been destroyed by a disgruntled employee, and the balance of power shifts inexorably away from him. Realizing the end is near, he consoles himself with a poker game, sharing the table with Ballister, the only ally left to him. The tension sharpens as Ballister is struck down by a blowgun under Prin’s collapsed fortress of control, and Prin reproaches him for dying at the moment of triumph when, in his view, he held a royal flush.
> "king of the river"
With his last illusion shattered, Prin steps out onto the balcony, only to be cut down by Malay spear-throwers as the final echo of his ambitions fades into the jungle night. The plantation he once ruled with fear and whimsy collapses around him, leaving Judith and David to reckon with the costs of escape, loyalty, and the fragile hope of starting anew in a world beyond Prin’s reach.
