On a quiet Australian beach, a hungover lifeguard named Josh (Xavier Samuel) asks his girlfriend Tina's (Sharni Vinson) brother Rowley to check the shark nets for him. Rowley is attacked by a shark. Rowley's death has a great psychological shadow on Josh and Tina. Josh feels guilty about his girlfriend. Josh gives up his job as a lifeguard and works as a tally clerk in a supermarket. Tina also goes to China to learn dance. A year later, when Tina returns to Australia, she meets Josh in a supermarket. At the same time, the supermarket is in turmoil, with theft and robbery... Just when this sudden incident is in full swing, the earth shakes, the tsunami comes overwhelmingly, the supermarket immediately becomes an isolated island, and a shark follows. A man-shark battle begins instantly...