After the owner of the largest canning factory in Dunkirk is murdered, the case is assigned to Captain Louise Poquelin, an overwhelmed single mother, and her new partner, Lieutenant Etienne de Beaumont, a cop with aristocratic origins. The two clash instantly, but over the course of the investigation, they discover that their differences are their greatest asset.

When a boarding school teacher is found dead along with a suicide note, it is presumed that she killed herself. But after the autopsy report indicates cyanide poisoning, Poquelin and de Beaumont suspect that it could be a homicide.

After Patrick Varney, an ex-cop turned thriller author, is killed during a writer's event, Poquelin and de Beaumont are put on the case. Solving his murder will prove difficult, however, as not only did the victim have many enemies but he was also Poquelin's former lover.

A protest by a group of vegan activists on an agricultural farm turns deadly when one of them is stabbed. Poquelin and de Beaumont discover that long-standing tensions have been simmering between the local farmers and the animal rights association over the exploitation and mistreatment of the livestock.