In the shadow of the Nazi occupation of Paris, a charismatic doctor named Marcel Petiot exploits the desperation of those fleeing persecution. Posing as an undercover ally, he lures victims into a deadly trap, promising them a safe escape from the city. As the war rages on, a relentless police investigation begins to unravel the horrifying truth behind his disappearances, leading to a chilling discovery at his home that exposes his true nature as a ruthless serial killer.