In an unnamed town, high school senior Julie James receives a sinister note from an elusive stalker telling her, "I Know What You Did Last Summer", referring to the previous year when Julie, her boyfriend Ray Bronson, Ray's best friend, Barry Cox, and Barry's girlfriend, Helen Rivers, accidentally killed a young boy named David Gregg after driving home from a party in the mountains to celebrate Ray and Barry's high school graduation. The four made a vow to never mention it to anyone, and drifted apart, Barry going to the local college, Helen dropping out of school, Ray taking off for California and Julie continuing to attend school. Fearful, Julie visits Helen, and informs her about the note. Barry is called but he assures the girls it is a prank and nothing more, as if anyone did know about their crime, they would inform the authorities and not write notes. The girls buy it, and Ray returns home to Julie, but is disheartened when she reveals she is now dating a fellow named Bud, and no longer wants to continue their relationship.

It is revealed that shortly after the night of the incident, Helen was chosen via a beauty contest to be the Channel Five Golden Girl, meaning she would be the studio's new television personality, much to the fury of Elsa, her sullen, envious and plain-looking older sister. At the Four Seasons, a luxury apartment complex where she lives, Helen is suntanning when she meets a boy, Collingsworth "Collie" Wilson, just out of the army. After she is done talking to Collie, she goes to her apartment and finds a magazine cut out of a boy riding a bicycle taped to the door.

Meanwhile, Ray is at his house and finds that he has been sent a newspaper clipping though the mail about the boy he, Barry, Helen, and Julie had killed last summer, David Gregg (in the updated version, the boy's first name is Daniel). In the article, it is revealed that his parents are Mr. and Mrs. Michael Gregg. Afterwords, the book takes the reader into a memory of Ray's, in which his father commented on his life; about having a popular football friend (Barry) and a cheerleader girlfriend (Julie) and Ray's father first meeting Barry. Ray then painfully remembers about the day it in which they ran over David Gregg and then called for help.

On Memorial Day, Barry receives a call. After he hangs up, he walks out of the University frat house where he leaves to meet the person who had called him. As it is dark, he does not see too well and is shot. When Ray finds out, he calls St. Joseph's Hospital to ask how Barry is doing. He is told that Barry is in surgery. Helen finds out about Barry being shot when she is in the TV studio. When Collie finds out about Barry he immediately goes to the studio to pick up Helen and take her to the hospital. When they reach the hospital, Helen and Collie are sent away by Barry's mother, who accuses Helen of calling Barry and getting him shot.

After Julie finds out, she receives a phone call from Ray asking if they could discuss what has been happening. She agrees to go with him. During the discussion the only thing the agree on is the shooter is not Helen. Then Julie suggests going to the Gregg's house to see if it is one of David's family members who is coming after them. After a little debating, Ray agrees to go.

When Ray and Julie get to the house, they use the excuse they had car trouble to get in the house. Megan Gregg lets them in. Ray goes to her kitchen and fakes making a call while Julie talks to Megan. While Julie and Megan talk, it is revealed that Megan is David Gregg's sister. Megan also says that her mother broke down after David's death and was sent to a hospital in Las Lunas. Her father moved to be close to her mother. To comfort her, Julie reveals she had lost her father at a young age. After Ray is done making his fake call, Ray and Julie leave. When they get back to the car, Julie confirms it obviously wasn't the Gregg family after them and tells Ray what she found out. They decide to go to Helen's apartment and tell her what they had learned from Megan. Elsa is at the apartment, tormenting Helen about the attack on Barry and reluctantly leaves after Julie and Ray arrive. Julie suggests it may be Elsa responsible for the threats and the shooting, as she has always resented Helen, and may have learned about it by accident, as Helen used to share a room with her. Ray calls the Cox family at the hospital. He finds out that since Barry was shot in the spine, he has paralysis and it may be permanent.

Ray then goes to the hospital and sneaks in to see Barry. While there, Ray tries to talk Barry into dissolving the pact of keeping the accident a secret. After Barry says no and lies that the shooting was a robbery and nothing to do with the accident, Ray leaves the hospital. Barry, however, thinks back to the night of the shooting, where he was lured out by an anonymous caller that supposedly had photographic evidence of the accident and would give the photos to Barry in exchange for money. Barry fell for it, agreed to meet the anonymous person at the University athletic field, and was shot.

On the way out of the hospital, Ray sees Bud and they decide to go have coffee together. While they talk over coffee, Ray says that he will get Julie back. Bud challenges him then says Julie will not go to Smith because of him. Later, Helen unexpectedly meets Collie in her apartment, who solemnly reveals himself to be David's older brother. He, darkly remembering, tells Helen that he was the one that shot Barry and is the one that left the picture on her door. He then tells her that he is going to kill her and the girl he is going out with later tonight. Panicking, she immediately runs to the bathroom and locks the door. When Collie begins to take the door off the hinges so that he can get in, Helen breaks the glass of the bathroom window and desperately escapes.

Julie prepares to go on a date with Bud, but then decides not to when her mother says she is worried and would like her to stay home. When she tells Bud, he convinces her to at least walk him to his car so they can talk. To Julie, Buds seems impatient and she realizes that she has never seen him act so angry. She remembers the first moment she saw Ray, after he came back from California, and realizes she doesn't want to date Bud anymore because she will always have feelings for Ray. When they get to Bud's car, he reveals that his name is really Collingsworth Wilson and that he was David Gregg's half brother. He tells Julie that he found out who had run down his little brother by asking a man who sold Julie the flowers she sent to David's funeral. He then starts to choke her. Julie is to the point of passing out when Ray saves her by beating Bud (Collie) with a flashlight. When the paramedics show up, they tell Julie and Ray about Helen's accident. Helen sent them to Julie's house, saying there would be someone trying to kill her. Julie then asks Ray how he knew of Bud intending to kill her and he tells her that Barry called him earlier and released him from the pact. After the phone call, he realized who Bud was. Then Julie asks Ray why Bud never tried to hurt him. Ray answers, "He did, tonight. He knew the worst thing for me would be to stay alive in a world without you."

там всё равно все померли

там тоже все померли /кажется/