TheI Know What You Did Last Summerlegacy sequel now has an official teaser poster and synopsis. The movie is the fourth feature-length installment in the slasher franchise, which originated in 1997 with a movie following the hook-wielding killer Ben Willis (Muse Watson) avenging a death that was covered up by a group of teenagers following a car accident the year before. TheupcomingI Know What You Did Last Summerstars Madelyn Cline, Chase Sui Wonders, Jonah Hauer-King, Tyriq Withers, Sarah Pidgeon, Lola Tung, and Nicholas Alexander Chavez alongside legacy stars Freddie Prinze Jr. and Jennifer Love Hewitt.

Sonyhas nowunveiled the teaser poster forI Know What You Did Last Summer. Although it does not reveal any of the faces of the new or returning characters, it does feature a hand holding a bloody hook. Whether the killer turns out to be a familiar face or a new vengeful person, the legacy of Ben Willis' iconic weapon remains firmly in place in the new movie. The blood dripping from the hook also seems to imply that the kills in the new movie will be particularly gory. See the full-size image below:

A hand holding a bloody hook on the teaser poster for I Know What You Did Last Summer 2025

They have also announcedthe official synopsis for the movie. The setup for the legacy sequel - which was directed by Jennifer Kaytin Robinson from a screenplay by Robinson, Leah McKendrick, and Sam Lansky - is almost exactly the same as the original movie. It will follow a group of five friends who “inadvertently cause a deadly car accident” and are “stalked by a killer” a year later. This leads them to seek help from “two survivors of the legendary Southport Massacre of 1997.” Read it below:

When five friends inadvertently cause a deadly car accident, they cover up their involvement and make a pact to keep it a secret rather than face the consequences. A year later, their past comes back to haunt them and they’re forced to confront a horrifying truth: someone knows what they did last summer…and is hell-bent on revenge. As one by one the friends are stalked by a killer, they discover this has happened before, and they turn to two survivors of the legendary Southport Massacre of 1997 for help.

Jennifer Love Hewitt looking at Brandy in I Still Know What You Did Last Summer

What This Means For I Know What You Did Last Summer

The Franchise Could Ignore Certain Sequels

This synopsis specifically calling Hewitt and Prinze Jr’s characters Julie James and Ray Bronson survivors of the “Southport Massacre of 1997"could potentially reveal that the movie will be in direct continuity with the original movie while ignoring the sequels. Both characters returned for the 1998 sequel to the iconicteen horror movie,I Still Know What You Did Last Summer, which is not mentioned in the synopsis. However, it is possible that the sequel is in continuity because Brandy, who was only inI Still Know, stated at one point that she was in talks to reprise her role.

Brandy played Julie James' new best friend Karla inI Still Know What You Did Last Summer.

Muse Watson as Ben Willis standing menacingly in I Know What You Did Last Summer

This approach to continuity is not uncommon, by any means.Other recent horror legacy sequels have streamlined pre-existing continuities, including 2018’sHalloween(which positions itself as a direct sequel to the original 1978 installment, ignoring the other nineHalloweenmovies), 2022’sThe Texas Chainsaw Massacre(also a direct sequel to the original installment), and 2021’sGhostbusters: Afterlife(which follows the first two installments, ignoring the 2016 reboot).

Our Take On The I Know What You Did Last Summer Update

Could Ben Willis Return?

IfI Know What You Did Last Summeris indeed ignoring later installments, the identity of the killer is called even more into question.Ben Willis wielded the hook in all three previous movies, as a living man in the first two and in spectral form in 2006’sI’ll Always Know What You Did Last Summer. While it makes sense to ignore that installment’s more supernatural turn, following directly from the ending of the 1997 movie means that Willis could very much be alive, as he was not canonically killed untilI Still Know.

I Know What You Did Last Summer (2025) Official poster)