‘I Know What You Did Last Summer’: Looking Back on the Slasher Classic 20 Years Later

Why the film starring Jennifer Love Hewitt and Sarah Michelle Gellar holds up today.

With Halloween quickly approaching, horror fans everywhere are in search of the next great scary movie. While 2017 has been a phenomenal year for the genre -- with standouts like Split, Annabelle: Creation, It and Get Out -- audiences need only to look back on the late ’90s slasher era for some of horror’s best thrills. 

The genre was more popular than ever thanks to the colossal success of Scream in 1996, with almost every major film studio attempting to recreate that same magic. Soon, everything from Urban Legends to a new installment of Halloween with Jamie Lee Curtis followed. Between 1996 and 2000, the horror genre was at an all-time high. So high, it almost became hard to keep track of them all. 

But one slasher film in particular stands out among the rest: I Know What You Did Last Summer, which came out 20 years ago on Oct. 17, 1997.

It’s not all that surprising, given the screenplay was written by Kevin Williamson, the very same writer behind Scream. Ironically, he actually wrote I Know What You Did Last Summer before Scream, but was unable to sell it until the latter’s monster success. Loosely based on author Lois Duncan’s 1973 suspense novel of the same name, I Know What You Did Last Summer is about four teenage friends being stalked by a killer one year after covering up a deadly car accident. 

Ben Willis

In more recent years, horror films have become a home for unknown actors, launching the careers of the likes of Anya Taylor-Joy (Split, The Witch) and Maika Monroe (It Follows). Twenty years ago, it was exactly where you wanted to be at the height of your career. I Know What You Did Last Summer cast some of the biggest stars of the late ’90s, including Jennifer Love Hewitt (Party of Five) as good-girl Julie and Sarah Michelle Gellar (Buffy the Vampire Slayer) as her pageant queen best friend, Helen. Freddie Prinze Jr. (She’s All That) and Ryan Phillippe (Cruel Intentions) rounded out the cast as their boyfriends, sensitive Ray and obnoxious Barry, respectively.

Aside from the film hitting a 20-year milestone, the cast has reason to celebrate as well. Despite their characters having no romantic connection, Gellar and Prinze began dating after they met on the set and eventually married; they now share two children together.

Following its release, the film was an undeniable hit, earning over $125 million worldwide at the box office. It even spawned two sequels, aptly titled I Still Know What You Did Last Summer and I’ll Always Know What You Did Last Summer. Both were critically panned and the series has been dead in the water since, but the original has stood the test of time and remains a staple in slasher history 20 years later. 

Helen Shivers

In addition to starring a hot young cast paired with the writer of the biggest horror film in years, I Know What You Did Last Summer owes much of its success to something few films were able to match at the time: conscience.

The characters are nowhere near as savvy as the teens of Scream, but what they lack in intelligence they make up for in guilt. The four leads are put through the emotional wringer before even coming face to face with their killer, making it all the more heartbreaking when they meet their eventual demise.

While the premise of a fisherman with a hook for a hand stalking you on July 4th is hardly relatable, the notion that committing a crime (for instance, running someone over with your car and dumping his body in the water…) can come back to haunt you is a universal fear. Hopefully, this film made some teenagers think twice before doing something stupid. (Though that’s unlikely.)  

Barry Cox

Another element the film nails is suspense. Williamson has been very public about the original 1978 Halloween being an inspiration for his screenplays, and I Know What You Did Last Summer is a perfect example of that.

Case in point: the slow burn of the killer. For much of the first half, the mysterious fisherman spends most of his time lurking in the shadows, spying on his prey. In fact, our hooded killer doesn’t make his first murder until almost 40 minutes in, making it all the more shocking when our leads start to bite it in the last act.

If audiences needed one more reason to watch this film, it is the nail-biting chase sequence between the fisherman and Helen. The pretty best friend being pursued by the killer is a stereotypical trope in all scary movies, but this scene is elevated thanks to the combination of Gellar’s superb acting and the heartbreaking end result. Audiences should fully prepare to be shouting at their screen in despair. 

Julie James

So, perhaps the next time you receive an anonymous letter without a return address, instead of opening the death threat you should consider revisiting this horror classic.

Whether it’s for the hip ’90s cast, the genuine scares or maybe you just have a thing for fishermen -- I Know What You Did Last Summer is sure to hook you (obvious pun intended) 20 years later.