Math Professor Sophie Knowles finds herself in the middle of an investigation after her friend, Henley College librarian, Charlotte Crocker, is found dead in the stacks. When Sophie learns that Charlotte wasn't the quiet, law-abiding citizen she seemed to be, she sets out to determine who her friend really was, and to find her killer. As she deals with a group of lottery players, winners and losers, the odds are Sophie will solve the puzzle.