This is a werewolf tale, by the famous author of The Man in the Iron Mask, The Count of Monte Cristo or The Three Musketeers.
"It is an exciting story of a diabolical pact; more than that it is an acute and merciless study of the corruption of a man's character by envy, and a colorful and ironic account of high and low life in rural eighteenth-century France. Like all Dumas stories it is lively, fast-moving, romantic without being sentimental, and always readable." ~ from the Introduction by L. Sprague de Camp
"Dumas's most successful supernatural work by far... an entertaining historical romance based on traditional legends of the werewolf."