Ellingham Academy in Vermont is full of riddles, twisting pathways, and winding gardens. Shortly after it is opened by Albert Ellingham in 1936, Albert's wife and daughter are kidnapped. The only clue is a riddle describing various methods of murder and signed, "Truly, Devious." Years later, true-crime buff Stevie Bell enters Ellingham Academy with a goal to solve the cold case. Then Truly Devious makes a surprising return, and another death rocks Ellingham Academy.