Plot
Captain Nolan is an Irish Canadian fisherman living in Newfoundland, who catches marine animals in order to pay the mortgage on his boat, "Bumpo", and eventually return to Ireland. Nolan's crew is looking for a great white shark on behalf of a local aquarium, but the shark targets the aquarium's representative, Ken. An orca intervenes and kills the shark, saving Ken's life.
Nolan switches targets to the much more valuable orca. He attempts to harpoon the creature but accidentally strikes a female orca instead, leaving her with a fatal wound. The female orca tries to commit suicide at the pain. Nolan and his crew get the orca on board, where she subsequently miscarries. The captain hoses the dead fetus overboard as the male orca, the female's mate, looks on and screams in anguish.
The enraged male tries to ram Bumpo. Nolan's first mate, Novak, cuts the dead female loose to distract their attacker, but the orca jumps the boat and takes him with it under the ocean. The following day, the orca pushes his dead mate onto the shore. Nolan agrees to kill the male, as the presence of an angry orca is causing the fish that are vital to the village's economy to migrate. The orca continues his vengeance by sinking several fishing boats and rupturing underwater oil pipes that deprive the villagers of fuel.
Rachel Bedford, a colleague of Ken and an experienced cetologist, shows Nolan how similar orcas are to humans. He confesses that he empathizes with the orca, as his own wife and unborn child were killed in a car crash caused by a drunk driver. Nolan promises Bedford that he will not fight the orca, but that night the whale attacks his home, resulting in crewmember Annie losing her left leg. After seeing her in the hospital, Nolan recruits his only other remaining crewman, Paul, along with Ken, Bedford, and Jacob Umilak, a Mi'kmaq hunter, to pursue the orca.
The crew chases the orca after he signals Nolan to follow him. Following an unsuccessful attempt to kill the orca with dynamite, Ken is leaning over the side when the orca surfaces and grabs him, killing him. They follow the orca until they reach the Strait of Belle Isle, but when Paul loses his nerve and tries to flee in the lifeboat, the orca smashes it, and he drowns. The next day, the orca maneuvers Nolan to collide with an iceberg. The captain harpoons the whale just as he and Bedford escape from the sinking Bumpo, but Umilak is crushed beneath an avalanche of ice after sending an SOS.
Nolan and Bedford hide on an iceberg, although Nolan slips onto another one to separate them and potentially save her life. The orca jumps onto the ice, causing it to tilt and sending Nolan into the water before catching him with its tail and hurling him to his death against the ice. A helicopter is seen coming to rescue Bedford. Meanwhile, the orca drowns himself by diving below the ice as the credits roll.
