After a violent boating accident, Sheriff Vernon Bourgeois joins forces with multiple agencies to recover a boat, and possibly a body, from the murky depths of the Mississippi waters. Meanwhile, Deputy Keith Bergeron and Sgt. Dudley DJ Authement, both raised on the bayou, head deep into the swamps in the middle of the night to investigate a hair-raising sighting of the legendary Rougarou, the local name for a "shape-shifting swamp monster." When the witness hands over video of the half-man, half-wolf creature prowling the weeds behind his camp, the officers have no choice but to explore the very woods where the mysterious beast disappeared. The next morning, Deputy Bergeron puts two and two together when he is called to the scene of a mutilated calf near where the Cajun swamp monster vanished