A boy locked in a tool shed fights off a dog biting his ankle until he manages to kill it with a hoe. The body of a young woman dressed as a bride is found in an abandoned swimming pool, and Zárate, a young inspector, notices that maggots are crawling out of incisions on the victim's head. Two BAC agents — the Criminal Analysis Brigade — take over the investigation, and the inspector doesn't take kindly to being sidelined.