As a serial killer targeting women terrorizes the city, María, Valentina, Gabina, and Ángeles join the first female police force.

María and the other Azules stumble upon a new victim of the Undresser and watch as a man they believe is innocent gets arrested.

The detectives take drastic measures to find answers. María seeks the help of someone who can offer new insight: a convicted serial killer.

María and Ángeles interview the adopted son of a woman named Rosa, who the Azules believe may have been the Undresser's first victim.