The movie begins with home movies of the three of them as little girls playing together and being the best of friends. Jenny does notice that her, Ellen, and Carla are going in different directions. At her home, Ellen sees her boyfriend, Dan with Jenny. At a picnic, Carla sees her ex-boyfriend, Steve with Jenny. The next day, Jenny goes out with Carla. Later that night, Carla calls Jenny's mother, Jean, asking where Jenny is. Jean is confused because she thought Jenny was with Carla. Jean starts calling around and no one knows where Jenny is. In the woods, two hikers are walking through and find a body. Sadly, the body is Jenny. The police arrive and inform Jean of finding Jenny's body.
The investigation soon begins with trying to find out who killed Jenny. Jean is at the police station speaking with Det. Staley who doesn't have many suspects yet. Det. Staley speaks with Carla about her story of Jenny leaving with guys in a red monte carlo. Det. Staley doesn't believe that story and tries to find more clues. Jean, upset about Jenny's death, goes hunting for Jenny's killer. Jean sees a news article with the description of how Jenny was killed and gets outraged. She speaks with Det. Staley, who doesn't know why the story is in the paper but is going to find out.
Ellen offers to move into Jean's house and help her find Jenny's killer. Jean accepts. She soon starts becoming like a daughter to Jean. Ellen thinks she belongs there and wants to replace Jenny.
Ellen calls Carla but Carla is nervous over the phone. She says that the police keep asking her about the red monte carlo but Ellen advises her to stick with the story and lets her know that she is staying at Jean's house. She advises for Carla to get a grip or she could end up in jail for the rest of her life. Ellen speaks with Kathy, another one of Jenny's friend, who is having nightmares and can't take it anymore and has to tell someone what really happened. Ellen threatens her and then Kathy leaves town.
Over the next couple of months, Ellen is helping Jean look at several different possible suspects but doesn't really know who killed Jenny. Jean soon discovers that she has to let it go and let the police handle the case. She tells Ellen she has to move out. Ellen gets upset but leaves. She then returns and gives a lie about how she remembered something about the killing. Det. Staley suspects Ellen but can't prove it.
A year passes, Kathy then returns, guilt has been on her mind the whole time, and tells Det. Staley what really happened. Ellen, Carla, Jenny and her drove towards the woods. Ellen and Carla start arguing with Jenny about stealing their boyfriends. They start punching her and kicking her. They cut off her hair. They stick her head in the creek water until she drowns. They threw a log over her to pin her down. After hearing Kathy's story, the police arrest Ellen and Carla for Jenny's muder. Their sentence is 15 years to life in prison.
Jean can finally put to rest her fight in trying to find Jenny's killer. She's standing on her porch looking up to the sky and whispers, "Good night, Jenny. Sleep with the angels."