Forty years ago, in the Canadian wilderness where rough men are searching for gold, “Chinaman” Shan Tung travels through a blizzard with his Great Dane, Tao. At the Telegraph Trail Bar, where they stop to rest, a bully cuts off Shan Tung’s queue to amuse the crowd. Reacting to the most serious insult in his culture, Shan Tung pulls out a knife and the bully shoots him dead. Several years later, Tao’s descendant, a fierce beast known as “Wapi, the Killer,” lives in the north at the shore of the Arctic Sea, owned and abused by “Sealskin” Blake, who runs the fur trading post. Meanwhile, far to the south, Dolores LeBeau lives with her father Baptiste and the many wild creatures she has befriended. When Peter Burke, a writer and naturalist employed by the government, comes to their cabin, he is welcomed, and soon he and Dolores are in love. When Peter must make a short business trip to Ottawa, Dolores helps him pack. Intrigued by the manuscript he has been writing, she sneaks it out of his bundle and he leaves without it. Nearby, a Canadian mounted policeman pursues Capt. Rydal, the master of a trading vessel who is fleeing murder charges. When the Mountie catches and tries to arrest Rydal, the villain’s cohort, who is concealed in the woods, shoots him. Rydal switches clothes with the dead lawman and the men proceed deeper into the woods, to where Dolores is swimming naked in the water with her pet bear Cubby. Seeing Rydal’s lecherous glances, she hides under a waterfall, while Cubby scares Rydal away. Wanting “to see more of the girl,” Rydal finds the LeBeau’s cabin and, pretending to be an injured Mountie, is taken in by the kindly Baptiste. Dolores is alarmed to find Rydal and his henchman there, but takes refuge in her room to read Peter’s manuscript. Later, when Baptiste leaves the cabin to chop wood, Rydal grabs Dolores, who struggles until she is unconscious. Hearing the sounds, Baptiste tries to rescue her, but the henchman fights him. Baptiste inadvertently kills the henchman, then fights Rydal, but is knocked out. When he regains consciousness, Rydal pretends to arrest Baptiste for the murder of his accomplice, but takes the bound man to a cliff above a river and pushes him over. Dolores, who has followed, jumps in and tries to save her father from the currents, but cannot. Returning for his manuscript, Peter finds Dolores pulling her father’s corpse from the water, while Rydal disappears. A year later, Dolores, now married to Peter and living in the city, yearns for the forest and its creatures. Although he must first carry out a government assignment that will take them to the Arctic Sea, Peter promises they will return afterward to the cabin. Onboard the trade ship Flying Moon , Peter works diligently in their sleeping room. When the captain, who claims to be ill and has not been seen by Peter or Dolores, finally sends for Dolores, she recognizes him as Rydal and realizes that she and Peter are at his mercy. Dolores decides not to reveal Rydal’s identity to Peter, fearing that Rydal will kill him, but Rydal soon renders Peter helpless by having his crewmen drop a sail on him. When the ship anchors near Blake’s trading post, Dolores tries to get help for the dying Peter, but Blake, who is another of Rydal’s cohorts, tells her there are no other ships in the area and that the nearest doctor is at Fort Confidence, two hundred miles across the Barren Lands. Rydal then announces that the ship will dock all winter, and Eskimo women are brought onboard for the sailors. As the days pass, Dolores manages to evade Rydal’s lecherous advances, sometimes by playing along until he passes out drunk. After deciding to appeal to Blake for help, Dolores walks through the snow to the bar. Seeing Blake whipping Wapi, she stands in front of the animal and protests the abuse. Her kindness, the first Wapi has ever known, inspires the animal to respond with gentleness toward Dolores. After Dolores again asks for Blake's help, he pretends to agree to provide her with two dogsled teams to transport her across the Barrens, but warns that attempting the trip in sixty below zero temperature is “almost certain death.” Secretly, Blake promises Rydal to return Dolores to him, but the eavesdropping Dolores overhears him. While she prepares Peter and herself for the journey, Wapi bites through his ropes and frees himself. When Blake presents Dolores with two dog teams, she pulls out a gun and tells him that she knows of his plans. After boarding Peter’s sled, she orders the Eskimo team master to leave, and when Blake tries to stop her, shoots him in the shoulder. Wapi, after which Rydal, upon learning of her escape, takes the second dog team in pursuit. Threatening the Eskimo with death if Rydal catches up, Dolores manages to keep her sled ahead, but then loses the gun, when it slips from her hands, and Rydal gets dangerously close. As her last hope, Dolores sends Wapi to attack Rydal and escapes with Peter to the fort. Wapi obediently attacks Rydal’s team, but is wounded in the battle. The Mounties at the fort search for Rydal, who is killed while fighting them. Dolores is nursing the recuperating Peter, when a limping Wapi shows up. Relieved that he has survived, Dolores promises to take the heroic animal home with her. Months later, in the woodland cabin, Wapi lives contentedly with Peter, Dolores and their baby, and the friendly, native creatures.