In 18th century France, the Chevalier de Fronsac and his Native American friend Mani are sent by the King to the Gevaudan province to investigate the killings of hundreds by a mysterious beast.
After completing his military training, young Léo, a taciturn soldier with family problems and secret addictions, is assigned to one of the units that patrol the streets of Paris in search of possible terrorist threats as part of Operation Sentinelle.
Trying to leave their troubled lives behind, twin brothers return to their hometown to start again, only to discover that an even greater evil is waiting to welcome them back.
