They didn't mean it. They didn't mean to hit the boy. There was a party, and it was an accident ... but they had futures to protect. So Barry, Julie, Helen, and Ray swore one another to secrecy. But now, a year later, someone knows. Julie receives a haunting. anonymous threat: "I know what you did last summer." The dark lie is unearthed, and before the four friends know it, they need to outsmart a killer ... or they will be the next to die.