In Alaska, in 1924, fishermen such as Jim Kimmerly keep a watchful eye on their government-controlled salmon traps, mindful of pirates who roam the waters. While heading home in his boat one day, Jim and helper Joe, both reformed pirates, reminisce about former partner Matt Kelly, who left the area after the government clamped down on illegal salmon hauls. Upon docking, Jim learns that a boat owned by a fisherman in the local co-operative was attacked by pirates, whose suspected leader is cannery owner Verne Williams. Hoping to prevent a violent confrontation, Jim tries to negotiate a deal with Williams, suggesting that the co-operative would pay to store half of its fish in his cannery if he put an end to the piracy. Williams, who deals in stolen fish because the co-operative has refused his low buying price, denies any criminal involvement and declines Jim’s offer. Jim then learns from inn owner Jackson that Matt has sent a letter to Jackson’s daughter Nicky, to whom Jim is engaged. Nicky reads the letter in front of Jim and admits that Matt, a former sweetheart, is returning soon and still has feelings for her. Worried that she will not be able to resist Matt’s charms, Nicky asks Jim to marry her immediately, but Jim refuses to force the issue. In another port, meanwhile, Matt is released from jail, where he served six months for poaching seals, and after losing over $200 playing roulette, skips out on paying for the repair of his boat, the Who Cares . Matt sails back to Nicky, who greets him warmly but insists she is not interested in him romantically. To prove otherwise, Matt kisses her passionately and lets Jim know he intends to pursue her. Despite Matt’s challenge, Jim is gracious toward Matt, his friend since childhood, and offers to get him into the co-op. Complaining that he owes $1,000 for the boat repair, Matt borrows $50 from Jim, then uses it to buy Nicky a birthday ring, the same gift Jim has bought for her. Later that day, while Jim, Matt and the other fishermen are on a salmon run, Jim starts to unload his surplus fish onto an iceberg and is startled when Matt’s boat whistle suddenly blares. The loud noise sets off an avalanche and Jim’s boat is destroyed. Although Jim accepts Matt’s lie that he blew the whistle accidentally, the other fishermen are suspicious and, back in the village, demand that Matt be ousted from the co-op. Matt then is greeted by Wycoff, the boat repairman who, unknown to Matt, learned about Matt’s whereabouts from Williams. Wycoff claims Matt’s boat as payment, but as he is pulling away from the dock, Matt jumps on board and knocks him out. With a bound Wycoff, Matt sails to Williams’ hideout and offers his services in exchange for $1,000 to pay off Wycoff. Williams agrees, and after the repairman is sent on his way, Williams and his men prepare to raid some salmon traps. In the village, meanwhile, Nicky anxiously awaits Matt’s appearance at her birthday party and admits to Jim that she is still unsure about her feelings. When word comes about suspicious boat activities near the salmon traps, Jim heads out to sea with the other fishermen. Williams and Matt manage to escape in Williams’ big boat, but two thieves left behind in a rowboat are shot and killed by the fishermen. After delivering the bodies to Williams’ hideout, Jim is accosted in the village by the co-op fishermen, who accuse Matt of being in league with Williams. Publicly Jim defends Matt, but later, in his room, questions Matt about his recent whereabouts. Matt denies any wrongdoing and insists that Jim is merely jealous. The two men brawl and after they both fall off the dock, Matt gets Jim to admit to Nicky that he was fighting over her and wants to get rid of Matt. Unhappy with Jim, Nicky agrees to consider Matt’s proposition that they leave together that night, and Matt goes to Williams’ hideout, demanding that they destroy the co-op cannery and use the distraction to raid all the salmon traps. Williams sends some of his men to set fire to the cannery, and during the attack, Joe is fatally stabbed. While most of the fishermen try to contain the fire, Jim catches up to Williams’ boat and exchanges gunfire with the pirates. After Jim shoots Matt in the shoulder, the pirates escape, and Jim returns to shore and tells Nicky the truth about Matt. Nicky then is surprised in her room by the wounded Matt but refuses to run off with him after informing him about Joe’s murder. Matt sneaks back to Williams’ hideout in a stolen motorboat and announces that Jim and the others will soon be coming after them. Armed with rifles and an automatic harpoon, Williams and Matt take off in Williams’ boat and attack Jim’s boat when it catches up to them. Matt stops Williams from shooting Jim, however, and while struggling with him, Williams shoots Matt. Though badly wounded, Matt sounds the boat’s whistle and steers the boat toward the icebergs. Williams’ boat capsizes in the ensuing avalanche, and later on shore, Jim acknowledges Matt’s sacrifice as Nicky embraces him.