The film is named after the protagonist Francisco Black aka "Paco" (Tomás Fonzi), a college student who starts using cocaine paste, a cocaine byproduct known as "paco".
Son of a senator, Francisco falls in love with a cleaning worker. He follows her into Buenos Aires' underworld only to find that his girlfriend has committed suicide after accepting to prostitute herself in exchange for drugs. Seeking revenge, Francisco places a bomb in the drug factory murdering several innocents. As a result of being accused of terrorism charges, his mother uses his influences to try to exculpate him, but she is forced to confine him in a detox clinic, where Francisco finds a bunch of lost souls.
Variety has called the film «an emotive character-driven rehab drama with a strong ensemble cast».