When Chief Inspector Armand Gamache is asked to provide crowd control at a statistics lecture given at the Université de l'Estrie in Quebec he is dubious. Why ask the head of homicide to provide security for what sounds like a minor even mundane lecture? But dangerous ideas about who deserves to live in order for society to thrive are rapidly gaining popularity fuelled by the research of the eminent Professor Abigail Robinson. When a murder is committed days after the lecture it's clear that within crowds can lie madness. The line separating good and evil right and wrong is quickly blurring - especially when the case leads unexpectedly close to home. . .

Part of the Inspector Gamache Series series.