Maigret's integrity is called into question when a childhood grudge conflicts with a new case.

Conflict rather than harmony probably reigned in eight out of ten of the still magnificent houses that surrounded the park. But he had rarely had the opportunity to breath such a strained atmosphere as the one between these walls.

Everything seemed fake, grating, starting with the lodge of the concierge-cum-manservant, who was neither a concierge nor a manservant, despite his striped waistcoat, but a former poacher, a murderer turned guard dog.

When a self-made man appeals to Maigret for protection at his lavish home, a years-old grudge from the past resurfaces and the inspector finds himself questioning his own motives.

Charged with the protection of wealthy butcher, Fumal, Maigret is torn between his sense of duty and a personal feud that is suddenly brought to the fore. When Fumal is viciously murdered, Maigret must overcome his ill feelings towards him and track down the murderer among the victim's many enemies . . .