Inspired by the adventures of Arsène Lupin, gentleman thief Assane Diop sets out to avenge his father for an injustice inflicted by a wealthy family.

A horrific discovery in a small town nestled high in the French Pyrenees begins to unravel a dark mystery that has been hidden for years. On an unforgiving winter morning, a group of workers discover the headless body of a horse, hanging suspended from the edge of a frozen cliff. Commandant Martin Servaz starts investigating and soon discovers a dark story of madness and revenge.