When the 19-year-old Brenda Beltrán, an aspiring actress, dies of intoxication after getting her first protagonist role in a soap opera, the Criminal Investigation Unit decides to take over the case. In the crime scene, they find a bottle with a liquid normally used to lose weight. After the autopsy, they uncover that she died from burns and from intoxication after ingesting sulfuric acid. The UNIC detectives decide to do a casting to catch the killer.