In a day where books are adapted into films on a regular basis, it’s typically interesting to revisit the original story, whether to experience it as the author intended or to compare with the screenwriters vision. With the recent release of the sequel/requel, Lois Duncan‘s I Know What You Did Last Summer shot to the top of my reading list. However, it was not what I had hoped it would be.
After a party, four teens are in a hit-and-run accident that results in a young boy’s death. Unable to deal with the consequences, they leave the body behind and make an anonymous phone call to the police, tipping them off.
The group makes a secret pact to bury the memory of that night and never speak of it again, but when one of the girls receives a note that reads, “I know what you did last summer,” their dark lie is unearthed. With twists and turns at every corner, they’ll have to fight to stay steps ahead of a killer determined to make them pay.
To be honest, I’d seen the 1997 slasher adaptation of I Know What You Did Last Summer a few times and recently watched the 2025 film before jumping into the 1973 novel. So I came in expecting a certain tale, but that is not exactly what I got. While differences should be expected, I will say I heavily enjoyed the 1997 and 2025 films plot a bit more.
The original novel was written for a younger audience, while the feature films are clearly geared towards a more mature crowd. The film leans heavily into the slasher territory, while the book is more of a psychological thriller with additional subplots. This is one of those times I wish I had read the original novel prior to seeing the films, I might have had a different feeling in the end.
Lois Duncan deserves credit for creating the core story and crafting a novel that that has become something bigger. That said, I stand by my sentiment that the overall tale featured in the films is more up my alley. Still, it’s always worth checking out the source material, which is why I recommend you take a peek at I Know What You Did Last Summer.
I Know What You Did Last Summer is available at bookstores everywhere from Little, Brown Books for Young Readers. The audiobook, narrated by Dennis Holland, is available via Libro.fm!


