Lois Duncan’s place in young adult literature is assured. Her books are popular with teenagers and valued increasingly by teachers and librarians. Books dealing with the theme of personal integrity are useful vehicles for classroom discussion. I Know What You Did Last Summer is a realistic novel laced with tragedy and one that provides no happy ending for all of its protagonists, which is a departure from traditional upbeat endings for young adult mysteries. Duncan’s work following this novel confirms her mastery of the suspense/mystery novel and her continuing interest in responsibility and group loyalty. In Killing Mr. Griffin (1978), another blend of morality and mystery, a group of teenagers are involved in a situation that turns unintentionally deadly. The selfishness of two of the group’s members leads them all into lives of guilt and lies. Susan is easily swayed when Mark decides to kidnap their English teacher. The teenagers are in the process of performing this act when the teacher has a heart attack and dies.
In 1992, Duncan became the fourth recipient of the Margaret Edwards Award. Sponsored by the American Library Association, the award recognizes writers whose books have given young adults a window that will help them understand themselves and their role in society. The books singled out by the award committee include both I Know What You Did Last Summer and Killing Mr. Griffin. The award committee cited Duncan’s diverse world of individuals: the fortunate, the underprivileged, the weak, the strong, the good, the evil, the impatient, and the submissive.
Duncan’s work has been praised by her readers, reviewers, and peers. A number of her novels have been honored by the Mystery Writers of America, The New York Times, and the American Library Association. All feature characters who struggle with truth and courage to reach maturity.