I Still Know What You Did Last Summer opens in the fictional town of Broken Ridge, Colorado, on a Fourth of July that will echo years later. Amber Williams, Brooke Nevin is there with her boyfriend Colby Patterson, [David Paetkau], and their friends Zoe, [Torrey DeVitto], Roger, [Seth Packard], and PJ, [Clayton Taylor], as they pull off a carnival prank. Roger dresses as the infamous Fisherman and the plan goes awry when PJ’s stunt ends with his body impaled on a tractor smokestack instead of safely landing on the mattresses. The town quickly believes the Fisherman is responsible, and the circle of friends decides to burn the evidence and keep what happened a secret.
A year passes, and Amber returns to town only to find that Colby’s internship in Los Angeles collapsed. Sheriff Davis, PJ’s father, harbors anger toward the group for PJ’s death, and Amber finds herself caught in the tension. She heads into the mountains where she crosses paths with Deputy Hafner, KC Clyde, one of the officers who witnessed the earlier accident. That night, Amber wakes to fifty text messages reading
> I know what you did last summer.
She then travels to Zoe’s shack, where Zoe, [Torrey DeVitto], offers shelter for the night. The following day, they come across Roger and Colby, but the pair are dismissed when the strange messages are brought up. As the danger grows, Amber is attacked on a ski-lift by someone wielding a hooked weapon.
A drunken Roger, tormented by guilt, contemplates suicide using the Fisherman’s hook. When he investigates a noise, he is attacked and killed by the Fisherman. The trio rushes to warn him, only to find Roger dead, accompanied by a suicide note and the hook. Deputy Hafner shows up to take statements, further tightening the net around their perception of who is watching them. Returning home, they discover yearbook photos of themselves sliced from older pages and arranged on a wall with the word “SOON,” escalating the sense that they are being targeted.
They hole up at Zoe’s place, where Lance, PJ’s cousin, [Ben Easter], appears outside and presents a message etched on his motorbike. He hints that the killer might be Sheriff Davis, deepening the suspicion against the town’s authorities. Colby suffers another brutal attack from the Fisherman while swimming, making the group realize they cannot stay. They decide to leave, but Zoe chooses to stay after learning that a major talent scout will attend the town’s festival where her band might finally get a break; a decision the others eventually support, choosing to stand together.
At the festival, Zoe performs before the crowd, and the Fisherman strikes again—ambushing Zoe, stabbing her, and tossing her from a balcony to her death. Sheriff Davis arrives on the scene, taking Amber and Lance captive at gunpoint, only to be killed in a dramatic reversal. The Fisherman targets Colby in a kitchen struggle, hooking him in the mouth and ending his life. Amber and Lance then encounter Deputy Hafner, who reveals that Roger had informed him about the earlier accident. The Fisherman turns his attention toward Hafner and impales him on a forklift, a brutal display of power.
Amber and Lance manage to get into a car and drive the Fisherman down, but the killer rises again. He is revealed to be the undead Ben Willis, the man responsible for the original murders eight years earlier. Ben attacks them, but Amber uses a hook to cut him and he disappears temporarily. The two rally to confront Ben, realizing the hook is the weapon that harms him. They chase him into a warehouse, where Amber finally confronts Ben and stabs him in the head, thrusting him into a thresher and ending his reign of terror.
A year later, Amber drives through a desert, and a tire blows out. She pulls over, cut off from reception, when Ben Willis’ ghostly silhouette returns behind her. The screen cuts to black just as Amber’s scream is silenced by the ominous sound of the hooked blade.
