On the island of San Juan, Felix and his partner Tony, two expatriate Americans who ply the Caribbean in their small craft the Ruby , are hired by a middle-aged American businessman to transport a woman named Irena to a neighboring island. The man explains that because the coldly beautiful and vaguely mysterious Irena has no passport, she is condemned to flee from country to country to stay one step ahead of deportation. The next morning, the shapely Irena boards the Ruby and is met with contempt by the callous, misogynistic Felix. Tony, an idealistic young rebel who fled the constraints of his family’s middle-class existence, is infatuated with the world-weary Irena. As Tony’s attraction grows more evident, Felix's antagonism toward Irena intensifies, resulting in the partners coming to blows. When an infuriated Felix lunges at Tony’s throat, Jimmy Jean, who works aboard the Ruby , pulls them apart. After dropping anchor one night, they all go ashore to attend a carnival. There, Irena asks Felix why he hates women, and he replies that he deserted his wife of six months because she bored him. Later, after Irena returns to the boat, Felix bursts into her cabin, but when he passionately embraces Irena, she icily turns away, stating that she is waiting for someone to touch her with kindness. Upon reaching their destination, Felix brusquely orders Irena ashore, prompting Tony to call him a brute and dissolve their partnership. A few days later at the hotel in which Tony and Irena have taken up residence, the clerk threatens to expose Irena to the authorities unless she "sleeps" with him. That night, when Tony asks Irena to marry him, she recalls the incident with the clerk and says that she is “all used up.” To earn enough money to start a new life with Irena, Tony seeks out Felix and proposes that they smuggle one last shipment of contraband, then sell the boat and split the proceeds. After warning Tony that Irena will destroy his life, Felix tells him to take the boat and go by himself. The next night, as Tony’s contraband-laden boat rounds the coast, a Coast Guard cruiser appears and orders Tony to let them board. After jumping overboard to avoid arrest, Tony, certain that Felix betrayed him, signs on as a crewmember aboard a Greek freighter. Soon after, the freighter collides with an ocean liner, gashing a hole in the freighter’s hull. In the crash, Tony is trapped below decks, pinned under a heavy metal beam. Dr. Sam, the port’s physician, is summoned to treat Tony. Because Tony is uncommunicative when the doctor questions him about his family, Doc searches his bunk and finds a photograph of Felix, Irena, Tony and Jimmy Jean. As the freighter limps into port, a fire smolders in its cargo hold filled with rubber tires. In the hold next to the tires, is a shipload of nitrate, and while the firefighters struggle to keep the flames from spreading into the highly explosive nitrate, Lt. Sellers of the United States Navy tries to extract Tony from the debris with a hydraulic jack. When word comes that the fire will rage out of control within twelve hours, Doc proposes freeing Tony from the beam by amputating his legs. When Tony refuses, Doc realizes that he must give Tony a reason to live. After Doc returns to shore, Jimmy Jean anxiously questions him about the accident. Recognizing him from the photograph, Doc asks Jimmy Jean to take him to the others in the hope of persuading Tony to change his mind. When the harbor master orders the ship to be hauled out to sea and abandoned, Lt. Sellers begs for one last chance to free Tony. Although the jack briefly lifts the beam, it comes crashing back down, dooming Tony to certain death. After the ship is towed out of the harbor, Jimmy Jean, Felix, Irena and Doc arrive at the docks and Doc asks Felix to accompany him to the freighter. Irena insists on joining them, and after Jimmy Jean pilots the craft to the freighter, Doc and Felix climb onboard to talk to Tony. Once below decks, Felix tries to convince Tony to go through with the amputation, promising that he and Irena will take care of him. After Tony rebuffs his offer, Felix asks Doc to leave. Once they are alone, Felix confesses that as an outcast, he felt a kinship with Irena and admits that he reported Tony to the Coast Guard because he was jealous of his alliance with her. Just then, an explosion rocks the ship, knocking Tony free. Hoisting Tony onto his shoulders, Felix climbs through the gash in the hull, jumps overboard and swims to the waiting boat. After the unconscious Tony is pulled aboard, they cast off just as the ship explodes into flames. Some time later, Irena and Felix are seated at a bar when Jimmy Jean comes to warn them that Tony checked out of the hospital and is armed with a gun. Tony then enters, approaches their table and asks to speak to Irena outside. When Irena turns and kisses Felix, Tony realizes that he has nothing to say to her. After pouring a shot from the bottle, Tony pays for a round of drinks and then walks out.