Prior to a new hotel opening on Amity Island, an enormous great white shark ambushes and kills two divers who are photographing the wreck of the Orca, the late Quint's boat. A couple of days later, their camera is recovered, and the shark goes after a female water skier and speedboat driver, devouring the skier while the driver fends off the shark using a gas tank and flare gun, causing the boat to explode, which kills her and severely burns the shark's face.
Along with these disappearances, a killer whale bearing large wounds is beached. Police Chief Martin Brody believes these events are the work of a shark. Brody explains his concerns to Mayor Larry Vaughn, who doubts the town has another shark problem. Later, Brody finds debris from the destroyed speedboat in the surf just off the beach. He wades over to retrieve it and uncovers the boat driver's burnt remains.