Lyon, 1898: The dismembered bodies of several women are found in the back alleys of the Croix Rousse neighborhood. Is it the work of a madman or a sect?

Six months have passed since Alexandre Lacassagne founded a crime-science team, and now they’ve been sent to the scene of a gory discovery. Who were these women whose decomposed bodies were found in the back alleys of the working-class Croix-Rousse neighborhood? And why were they placed there, as though on a sacrificial altar? Is it the work of a madman or a sect? The old morgue-boat is called back into service. At the top of his form since his friend Freud started giving him hypnotism sessions, Félicien will slowly piece together the elements of this strange puzzle. Meanwhile, Irina, a journalist at Le Progrès, is working on the investigation from inside the Vinatier insane asylum, where she has been committed.