Five years after the dramatic events that brought Season 8 to a close, Inspector Rocher is being primed to become Commissioner. Jess has passed all her tests to become Lieutenant; she and Hyppo are now married. Meanwhile, Adèle has left Paris and quit the police force. She is about to marry the man of her dreams, when she is called to weigh in on a particularly violent and strange murder: the corpse of a woman found inside a dead bull. Adèle feels irresistibly drawn back to her criminology work - and to Rocher.