The film is based on true events about the 'Monster of the Mangones'; apparently Adolfo Aristizabal,[2][3] a sadist, psychopath who murdered 30 children between the ages of 8 and 13 and an unsolved case in the Colombian justice system.
They were mostly street dwellers or young people who walked near the Mangones; an area of Cali where there were unbuilt spaces and buildings are isolated from each other, making it easy to capture anyone in the dark of night.
To this was added the myth that the person presumed responsible for these deaths was a wealthy man who suffered from leukemia and the appearance of him was dying and cadaverous.
The narrative moves to an airport where a charter lands and from the interior Roberto Hurtado, a wealthy but weak and ill old man, gets off, accompanied by his son, Adolfo, and Dr. Hughes, his family doctor.
At the office, Dr. Hughes explains to Adolfo that his father suffers from a rare blood disease which is poisoning him and has given him a monstrous appearance (which would alter his sanity) as well as Thrombocytopenic purpura.
The population and the press speculate that they are victims of the 'Monster of the mangones', an alleged serial killer who rapes young men alone or with a gang, apparently wealthy and homosexual that traffics blood.
Without saying anything to his father, Adolfo asks him for money to fix the problem, citing threats to the family, but Roberto, also aware of the assault flatly refuses.
While Adolfo changes labels from a useless blood and a usable one, he goes to his office and burns various documents including the photos of the murder, takes a suicide pistol and falls on his fish tank.
During a weekend walk on the river bank; Perfecto, Ever and his family, and Florencia find out about the capture of the so-called 'Monster of the mangones'; Pedro Luis Mosquera alias 'Babalú' who confessed the crimes even to the press (archive footage).