I Know What You Did Last Summer is a 1997 American slasher film based on the 1973 novel of the same name by Lois Duncan. The film stars Jennifer Love Hewitt, Sarah Michelle Gellar, Ryan Phillippe and Freddie Prinze Jr., with Anne Heche and Bridgette Wilson appearing in supporting roles. It centers on four friends who are being stalked by a killer, one year after covering up a car accident in which they were involved. The film was directed by Jim Gillespie, from a screenplay written by Kevin Williamson, writer of Scream. The film was followed by two sequels, I Still Know What You Did Last Summer (1998) and the straight-to-DVD release I'll Always Know What You Did Last Summer (2006). Though the former film sees a continuation of the plotline established in its predecessor, the latter film establishes a new plotline and does not star any cast members from the previous two installments.
