"I Know What You Did Last Summer" is a 1997 American slasher film about four teenage friends who accidentally hit a man with their car and dump his body in the sea, agreeing to keep it a secret. One year later, they are stalked by a hook-wielding killer who apparently knows what they did. The plot follows their struggle with guilt and the terror of being hunted as the killer targets them one by one.
There is also a more recent 2025 sequel film of the same franchise, set 27 years after earlier events, where another group of friends is targeted by a killer after covering up a fatal car accident. The film involves themes of secrets, revenge, and survival.
If a more detailed summary or specific aspect of the story is desired, please specify.