After celebrating their high school graduation, Julie, her boyfriend Ray, and their friends Helen and Barry accidentally run over a man on a coastal road in their hometown. In a panic about ruining their futures, they decide to dump the body into the water and vow to never speak of it again. A year later, Julie has become withdrawn and guilt-ridden. Returning home from college for the summer, she receives an anonymous letter that reads, "I know what you did last summer." Terrified, she reconnects with Helen, Barry, and Ray. The group realizes someone knows their secret — and it's clear that the person is stalking them. As the summer progresses, mysterious and violent events unfold. Barry is attacked, Helen is stalked, and Julie discovers that the man they thought they killed — David Egan — might not have been who they hit. Investigating further, Julie learns that David had a tragic past: his fiancée Susie died in a car accident, and he was suspected of committing suicide. However, Julie uncovers that Ben Willis, Susie's father, actually killed David in revenge and was the man they accidentally hit that night. Ben Willis survived the hit-and-run and is now seeking revenge on the teens for trying to cover up his "death." In a brutal night of terror during the town's Croaker Festival, Helen and Barry are killed, leaving only Julie and Ray. Julie is chased onto Ben's fishing boat, where she uncovers evidence of his obsession with them. She and Ray ultimately manage to wound Ben and knock him into the ocean, but his body disappears — leaving his fate uncertain.One year after the events of the first film, Julie is trying to move on with her life, now attending college in Boston. However, she is still traumatized by her past encounter with Ben, the fisherman who tried to kill her and her friends. Julie suffers from terrible nightmares and anxiety, straining her relationships — especially with Ray, her boyfriend who stayed behind in their hometown. Julie’s roommate Karla Wilson wins a radio contest — supposedly — and is told she can bring friends on an all-expenses-paid vacation to the Bahamas at a resort called Tower Bay. Julie invites Ray, but he declines at first, so Karla’s boyfriend Tyrell Martin and their friend Will Benson end up going instead. They arrive at the Tower Bay Resort just as the off-season starts — meaning a huge storm is coming, most staff are leaving, and the place is eerily empty. The resort workers they meet include the bartender Nancy, the manager Mr. Brooks, and a few others. Soon after they arrive, strange things begin happening and Ooe by one, resort staff and guests are murdered by a figure wielding a large hook, just like the year before. Julie becomes convinced Ben Willis is alive and hunting them again. Meanwhile, Ray realizes something is wrong after being attacked while trying to get to the island. He commandeers a boat and heads for Tower Bay to rescue Julie. It’s revealed that the whole "vacation" was a setup — Julie and her friends were lured to the island by Ben Willis, who rigged the radio contest. The killings at the resort are part of his revenge plot. In a shocking twist, Will Benson, the seemingly sweet and helpful friend, is actually Ben Willis’s son. He helped orchestrate the whole thing. In the final showdown Tyrell is killed, Karla fights for her life but survives, Julie confronts both Ben and Will and Ray arrives in time to help.Julie kills Ben by shooting him multiple times, and Will is also killed. In the end, Julie, Ray, and Karla are the survivors of the Tower Bay Massacre. Months later, Julie and Ray are living together, seemingly safe — but Julie is still haunted by Ben (or a hallucination of him), who grabs Julie from under her bed, leaving it ambiguous whether it’s real or just her lingering trauma.

Julie enrolled at University of North Carolina, Chapel Hill, majoring in Psychology with a focus on trauma and memory. She chose this path as an attempt to understand what had happened to her own mind.Julie James, one of the original survivors of the Southport massacre, has since become a college professor and lives alone. Ava seeks her out for help after the murders begin again, and though Julie is reluctant to revisit that chapter of her life, she agrees to offer guidance. She warns Ava that pursuing the killer alone is dangerous, which leads to conflict with her ex-husband Ray, who blames her for encouraging Ava to investigate. Time flew by now that she and Ray are working things out, and hoping to be remarried again, and start their own little family as well.Julie and Ray attend joint therapy, confronting the night’s trauma and the subsequent years of mistrust. Ray apologizes for his past aggression, admits he never fully processed his own guilt, and promises to “never let fear dictate love again.”Julie and Ray have begun to discuss adoption. They’ve been fostering a teenager, Mika, who lost her parents to a car accident a year earlier and has been staying with them for six months. Julie still visits the beach alone, sometimes with Ray, sometimes alone, but now she can hear the wind without it screaming. She still writes letters to Helen, but now she also writes to herself, reminding herself: “You are not the night; you are the sunrise after it.”