UNIC investigates Miguel's death. The autopsy reveals that one of the objects used by the criminal is a training collar for dogs and finds, in the cadaver, a tattoo of a woman's name. Miguel had a dog called Bella. The detectives decide to investigate the place where Bella was adopted. Meanwhile, a new body is found. Detective Vargas recognizes the victim, who she saw a day before in the veterinary with her daughter and their dog. The group of detectives realizes that there are several similarities between the cases.
