In Los Angeles, the LAPD Detectives Max Dire and Jim "Jimmy" Sheldon are partners and friends. Max is married with Anna Dire and Jimmy intends to leave the force to marry his fiancée Helen. When there is a call in a club with three sadistic killers, Max and Jimmy breaks in through the ventilation ducts. However, one of the criminals hears a noise in the duct and shoots Jimmy, while Max kills them three. Jimmy is dying in the hospital when a man injects a serum and Jimmy mysteriously recovers and becomes powerful. When Jimmy commits suicide and Max has problems with his marriage with Anna, the high-ranking police officer Adam Garou invites him to join his special force team formed by the decorated officers Casey Spencer, Doug Crane, Liza and Ramon Perez. They invite Max to follow them in one assignment during the night and they inject a mysterious substance that makes them stronger and slaughter a gang of criminals. Max refuses to inject himself and to join the group of vigilantes, but later Casey shoots him, injects the serum and he instantaneous heal. Soon he finds that the substance is indeed extracted from Garou's brain, who is a werewolf.
—Claudio Carvalho, Rio de Janeiro, Brazil