Following a painful divorce Cassandra James takes up a lectureship in a Cambridge College. When her friend and colleague Margaret Joplin dies of an apparent poolside accident, James becomes the acting head of the English Department, as well as the deceased's literary executor. An inspection of Joplin's private papers soon leads James to suspect that foul play was involved in her death and that she herself might be the killer’s next target. Will her skills in solving literary puzzles help her to unmask the assassin?