Julie, Ray, Helen and Barry have all tried to move on, to forget about what happened. But it seems that what happened the previous summer can't be erased. Julie is the first to realize this when she receives a letter that says: "I know what you did last summer."She can't believe that someone knows what happened and the others can't either. They try to find explanations, but they realize soon that there is none. Someone knows what they did and they could all be in danger.I know there is a movie based on this book. I've never seen it, but I have wanted to read the book for quite a while. I don't think I will be seeing the movie because I know it will do no justice to Lois Duncan's book. This book is intense, suspenseful and a real page-turner. I couldn't wait to find out what happened next. Julie and Ray are good characters. They want to do the right thing, but are just afraid. I like Helen too, but at times she did frustrate. What I will say though, is that she does stick by those she loves. Barry is the most who frustrated me the most. Barry was all about himself, but even in the end, he had a heart too. Overall, great book. I couldn't put it down.