The incredible new book in Louise Penny's #1 bestselling Chief Inspector Gamache series.

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. Yet for every person seduced by her theories there is another who is horrified by them. When a murder is committed days after the lecture, it's clear that within crowds can lie madness.

To uncover the truth, Gamache must put his own feelings about the divisive Professor to one side. But with her ideas gaining ground, the line separating good and evil, right and wrong, is quickly blurring - especially when the case leads unexpectedly close to home ...

PRAISE FOR LOUISE PENNY AND THE INSPECTOR GAMACHE SERIES:

'Louise Penny is one of the greatest crime writers of our times' DENISE MINA

'She makes most of her competitors seem like wannabes' THE TIMES

'Gamache has become to Canada what Hercule Poirot is to Belgium' THE NEW YORK TIMES

'Louise Penny twists and turns the plot expertly tripping the reader up just at the moment you think you might have solved the mystery' DAILY EXPRESS

'The series is deep and grand and altogether extraordinary . . . Miraculous' WASHINGTON POST

'No one does atmospheric quite like Louise Penny.' ELLY GRIFFITHS

'An absolute joy' IRISH TIMES