A young stevedore takes on the mobster who rules the docks.

At the request of mob boss Johnny Friendly, longshoreman Terry Malloy, a former boxer, lures fellow dock worker Joey Doyle to the roof of his tenement building, purportedly to discuss their shared hobby of pigeon racing. Believing that Friendly only intends to frighten Joey out of his threat to speak to the New York State Crime Commission, Terry is stunned to see Joey topple from the building as he and his brother, Charley "the Gent," watch from across the street. As neighbors gather around Joey's body, his distraught sister Edie accuses parish priest Father Barry of hiding behind the church and not helping the neighborhood break free from the mob's grip. Listening nearby, Terry is disturbed by Edie's indictment and later joins Charley, Friendly's lawyer and accountant, at a meeting with Friendly and his lackeys. Friendly assures Terry that Joey's death was necessary to preserve his hold on the harbor, then directs dock manager Big Mac to place Terry in the top job slot the following day. The next morning, while waiting for the day's work assignment, the dock workers offer their sympathy to Joey's father Pop, who gives Joey's jacket to Kayo Dugan. Terry is approached by Crime Commission representative Eddy Glover, but refuses to discuss Joey. Edie comes down to the docks to apologize to Father Barry, but he admits that her accusation has prompted him to become more involved in the lives of the longshoremen. Father Barry asks some of the men to meet downstairs in the church, despite being advised that Friendly does not approve of union meetings. Later, in the warehouse, Charley asks Terry to sit in on the church meeting. When Terry hesitates, Charley dismisses his brother's fears of "stooling." Despite the sparse turnout, Father Barry adamantly declares that mob control of the docks must end and demands to know about Joey's murder. Several men bristle in anger upon seeing Terry at the meeting, and Kayo tells Father Barry that no one will talk out of fear that Friendly will find out. Father Barry insists the men can fight Friendly and the mob through the courts, but the men refuse to participate. Friendly's stooges break up the meeting by hurling stones through the church windows. After Pop and Kayo are attacked outside, Father Barry presses Kayo to take action and Kayo agrees. Terry insists on walking Edie home and, on the way, she hesitatingly tells him abut her convent upbringing and ambition to teach. At home, Pop scolds Edie for walking with Terry, whom he calls a bum, and demands that she return to college. Edie responds that she must stay to find out who killed Joey. Later that day Edie is surprised to find Terry on the roof with Joey's pigeons. Terry shows her his own prize bird, then asks her if she would like to have a beer with him. At the bar, Terry tells Edie that he and Charley were placed in an orphanage after their father died, but they eventually ran away. He took up boxing and Friendly bought a percentage of him, but his career faded. Swept up among wedding party revelers, Edie and Terry dance together until they are interrupted by Glover, who serves Terry with a subpoena to the Crime Commission hearings. Edie demands to know if Friendly arranged Joey's murder, and when Terry cautions her to stop asking questions, she accuses him of still being owned by the mobster. That evening, Friendly visits Terry, who is evasive about the church meeting, then surprised when Friendly reveals that Kayo testified before the commission. Charley criticizes Terry for seeing Edie, and Friendly orders Terry back to working in the ship hold. The next day in the hold, Terry attempts to speak with Kayo, but the older man brushes him aside, calling him one of Friendly's boys. Big Mac and one of his henchmen rig a crane to slip, and a load of boxes crashes down upon Kayo, killing him in front of Terry. Outraged, Father Barry gives an impromptu eulogy for Kayo, asserting that Kayo was killed to prevent him from testifying. After two of Friendly's henchmen begin pelting the priest with fruit and vegetables, Pop and Edie arrive and watch as Father Barry ignores the abuse and exhorts the men to believe in themselves and reject mob control. Terry furiously knocks out one of the henchmen, angering Friendly and Charley. Later, Father Barry returns Joey's jacket to Pop and Edie. That night, after Edie gives Joey's jacket to Terry, the guilt-stricken Terry tries but is unable to tell her about his part in Joey's murder. The next morning Terry seeks out Father Barry to ask for guidance as he believes he is falling in love with Edie, but is conflicted about testifying and about going against Charley. Father Barry maintains that Terry must follow his conscience and challenges him to be honest with Edie. When Terry meets Edie on the beach later, he relates the details of the night of Joey's murder, insisting that he did not know Joey would be killed, but Edie rushes away in distress. Later while tending his pigeons on the roof, Terry is visited by Glover and implies that he might be willing to testify. Their meeting is reported to Friendly, who orders Charley to straighten Terry out. That night, Charley takes Terry on a cab drive and chides him for not telling him about the subpoena. When Terry attempts to explain his confusion, Charley brusquely threatens him with a gun. Hurt, Terry reproaches his older brother for not looking after him and allowing him to become a failure and a bum by involving him with the mob. Charley gives Terry the gun and says he will stall Friendly. Terry goes to see Edie, and breaks down her apartment door when she refuses to let him in and demands to know if she cares for him. Edie tells Terry to listen to his conscience, which angers him, but the two embrace. When Terry is summoned to the street, Edie begs him not to go, then follows him. After the couple is nearly run down by a truck, they find Charley's body hung up on a meat hook on a nearby fence. Taking down his brother's body, Terry vows revenge on Friendly, and sends Edie for Father Barry. Armed, Terry hunts for Friendly at his regular bar, but Father Barry convinces him that the best way to ruin Friendly is in court and Terry throws away the gun. The next day at the hearings, Terry testifies to Friendly's involvement in Joey's death, outraging the mobster, who shouts threats at him. Back at home, Terry is scorned by the neighbors for testifying and discovers that his pigeons have been killed by a boy he once coached. Edie attempts to comfort Terry, advising him to leave, but Terry insists that he has the right to stay in his town. The next day Terry reports to work as usual, but is ignored by the men and refused work by Big Mac. In his office at the pier, Friendly, who is about to be indicted, swears vengeance on Terry. Terry confronts Friendly on the pier, declaring he is nothing without guns, and the two fall into a brutal fistfight. While Friendly's men help to thrash Terry, the dockworkers watch impassively as Edie arrives with Father Barry. Friendly orders the longshoremen to begin unloading, but the men refuse and demand that Terry be allowed to work, hoping the shipping owners will witness their refusal to obey Friendly and realize their intention to restart a clean union. Father Barry urges on the beaten Terry, who rises and defiantly stumbles down the pier and into the warehouse.