Madrid, summer of 2010. Commissioner María Ruiz investigates the sinister crime of a young man. With no visible identity and no clues or apparent motive, María will begin an investigation that will become more and more complicated.

The storyline kicks off in 1976, when 16-year-old Bea (played by Alicia Falcó) is swept up in the winds of change blowing across Spain, as she teams up with the women demanding the approval of the right to abortion. This act of rebellion will intertwine with an unexpected feeling when she meets Miren (played by Elena Tarrats), with whom she strikes up a very special friendship. All this will turn that summer into a decisive stage of her life.