Still reeling from the loss of her mother, medical student Nancy Adams (Blake Lively) travels to a secluded beach for some much-needed solace. Despite the danger of surfing alone, Nancy decides to soak up the sun and hit the waves. Suddenly, a great white shark attacks, forcing her to swim to a giant rock for safety. Left injured and stranded 200 yards from shore, the frightened young woman must fight for her life as the deadly predator circles her in its feeding ground.