Witnessing a mob-related murder, single mother Rosa is forced at gunpoint into clearing up the crime scene. Her spotless work gets her noticed by the criminal family responsible for the killing.
The body of the murdered boxing manager is found and detectives Sandro and Gutiérrez are called in to investigate. The evidence leads them to the boxing club, and to their first encounter with Rosa.
While Rosa's son's health rapidly deteriorates, Sandro and Gutiérrez locate another murder victim, finding a potentially incriminating weapon at the scene.
As Felipe's condition deteriorates, Rosa devotes herself fully to her criminal activities in order to save money and take him to the US for a cure. In another part of town, her friend María attends a casting call and mysteriously disappears.
While suspended Detective Sandro uncovers more clues to the missing girls case, Detective Gutiérrez begins to follow his colleague's investigation hypothesis.
When Emilio is arrested, Rosa confesses all to Sandro. Seeing this as an opportunity to bring down the crime syndicate, Sandro convinces Rosa to gather evidence on her employer's illegal activities.
