‘I Know What You Did Last Summer’: 5 Major Changes Amazon’s Series Makes to the Classic Horror Movie

The 1997 horror hit I Know What You Did Last Summer updated Lois Duncan’s 1973 book for the ‘90s. The new Amazon series again updates the story for 2021, and takes even more liberties with the book and movie. Here are five key differences between the new show and the classic movie. 

[Spoiler alert: This article contains spoilers for the season premiere of I Know What You Did Last Summer and the 1997 movie.]

Madison Iseman gasps in horror with Ezekiel Goodman
Madison Iseman and Ezekiel Goodman | Michael Desmond/Amazon Studios

The ‘I Know What You Did Last Summer’ show has all new characters

The 1997 horror movie uses the same character names from the book: Good girl Julie (Jennifer Love Hewitt), philosophy scholarship student Ray (Freddie Prinze Jr.), beauty queen Helen (Sarah Michelle Gellar), and jock Barry (Ryan Phillippe). The Amazon series invents all new characters, including a set of twins. 

Lennon and Allison (Madison Iseman) are twin sisters who couldn’t be more different. Lennon is a bisexual party aninal. Allison is a virginal, studious introvert. Margot (Brianne Tju) is Lennon’s girlfriend and a social media influencer. Riley (Ashley Moore) is the daughter of a drug dealer trying to make good. 

I Know What You Did Last Summer cast stands on the road
L-R: Sebastian Amoruso, Brianne Tju, Madison Iseman, Ezekiel Goodman and Ashley Moore | Michael Desmond/Amazon Studios

Johnny (Sebastian Amurosu) is a jock but he’s also openly gay, unlike womanizer Barry. Dylan (Ezekiel Goodman) pines for Allison. 

‘I Know What You Did Last Summer’ notes begin far more escalated on the show

The movie begins with Julie getting handwritten notes that read, “I know what you did last summer.” The notes escalate as the movie progresses, ramping up the horror, including some writing on mirrors. 

Amazon’s I Know What You Did Last Summer goes there right away. The first note Lennon receives is already scrawled on her mirror, and a bloody goat’s head is there to boot. 

Madison Iseman sees I Know What You Did Last Summer written on the mirror
Madison Iseman | Michael Desmond/Amazon Studios

A change of scenery 

Duncan never named the town in her book. The 1997 movie set the events of I Know What You Did Last Summer in Southport, North Carolina, a real East Coast beach town. Amazon’s series films in Hawaii, where the show takes place. 

This gives the show quite a different look from the movie. It also lends the killer use of its indigenous goats, among other island paraphernalia. The automobile accident in question and the subsequent stalkings and killings now bring the horror to paradise, not just Anytown, U.S.A.

This ‘I Know What You Did Last Summer’ has a different victim

In the movie, the group hits Ben Willis (Muse Watson)’s son Will with their car. Willis comes after them to avenge his child. Just as the main characters of the Amazon series have changed, so has their victim. It’s not even a man, but this time they hit a woman. 

I Know What You Did Last Summer: Sebastian Amoruso stands between headlights
Sebastian Amoruso | Michael Desmond/Amazon Studios

In the movie, they also had to finish the job. Will woke up as they were dumping the body so they delivered the death blow. On Amazon’s I Know What You Did Last Summer, the victim dies from the impact of the car accident. The friends are responsible for disposing of the body, but they didn’t finish her off. 

Social media exists now 

In 1997 the internet was still new, as evidenced by movies like The Net and Hackers. It wasn’t really a part of I Know What You Did Last Summer. Social media wouldn’t exist for another decade. If it had, Helen would have probably been all over it. 

Ashley Moore rides her bike and Ezekiel Goodman walks in horror series I Know What You Did Last Summer
Ashley Moore and Ezekiel Goodman | Michael Desmond/Amaozn Studios

‘I Know What You Did Last Summer’: What Jennifer Love Hewitt, Sarah Michelle Gellar, Freddie Prinze. Jr, and Ryan Phillippe Wanted to Know About the New Show

Amazon’s I Know What You Did Last Summer exists in the modern social media era. Not only is Margot an influencer, but the killer can use social media as another tool to stalk and threaten the gang. 

New episodes of I Know What You Did Last Summer premiere Fridays on Amazon.