A society lady has been poisoned to death at her own party, and a search of the body has turned up a mysterious enciphered message. The press speculates about spies and atomic secrets, and the police need the code broken before a Red Scare sets in. So they go to Professor Leland Truffault. Haunted by his wartime experiences as a cryptographer at Bletchley Park, he now hides in academia at Laurelhurst University. But the secret message draws him out...as does the hunt for a sly and ruthless killer. Racing against time as police close in on the wrong suspect--one he dearly wants to keep safe--Truffault risks it all to take part in a deadly game. But the professor knows a thing or two about how a game is played, and he won't quit before the last move.