A lone girl on a night swim disappears. What's left of her body washes up on shore the next day, but it's enough to alert the local authorities that there's probably a shark in the area. Police Chief Martin Brody (Ray Scheider) tries to reassure the populace, when bowing to pressure, he keeps the beach open to tourists. Then a little boy disappears from the water near the beach, and the beach is closed. Chief Brody is joined by Marine Biologist Matt Hooper (Richard Dreyfuss), and a reward posted by the missing boy's mother attracks professional shark hunter Quint (Robert Shaw). Together they head out in a small boat to conquer the shark. There are several sightings of the shark, and after the shark kills an Orca, Quint manages to shoot harpoons into it to attach flotation barrels. The shark drags the boat, floods the engine, and breaks loose. Hooper tries going down in a cage to shoot poison into the sharks mouth. The shark only destroys the cage while Hooper hides out underwater. Quint and Brody haul in the cage remains when the shark throws itself onto the boat, and Quint is gone. Desperate, Brody throws an air tank into the beast's mouth. He next uses Quint's harpoon gun to shoot and explode the air tank and the shark. Hooper reappears, and the two men swim ashore.