Inspired by the 1997 American drama Donnie Brasco, El Dandy tells the story of a law professor who has been hired by the Attorney General, to participate in a program of special operations, where you must infiltrate one of the most notorious drug cartels of Mexico City. Under the false name Daniel "El Dandy" Bracho, begins the task of identifying all the members of this clandestine network. However, he quickly finds that his acute ability to police work is only comparable with the exciting sense of danger that experiences living life to the fullest. Along the way, it avails itself of the help of a criminal's petty, loyal, even corrupt, called El Chueco, who quickly befriends Bracho and comes dangerously close to discover his true identity. Much deeper Bracho is involved in the mafia, more work tells him to get out, and the professor once incorruptible has to choose between returning to a normal life as a respectable citizen or fully embrace his criminal life.