After four high school friends are involved in a hit-and-run road accident, they dispose of the body and vow to keep the incident a secret. A year later, they each start receiving anonymous letters bearing the warning "I Know What You Did Last Summer."
Ever since killing the Fisherman one year ago, Julie James is still haunted by images of him after her. When her best friend Karla wins free tickets to the Bahamas, Julie finds this a perfect opportunity to finally relax. But someone is waiting for her. Someone who she thought was dead. Someone who is out again for revenge.
High school hotshot Zach Siler is the envy of his peers. But his popularity declines sharply when his cheerleader girlfriend, Taylor, leaves him for sleazy reality-television star Brock Hudson. Desperate to revive his fading reputation, Siler agrees to a seemingly impossible challenge. He has six weeks to gain the trust of nerdy outcast Laney Boggs -- and help her to become the school's next prom queen.