Lucía is arrested while driving her boyfriend Héctor's car at 200 km/h, dazed and bloody. She was sharing a weekend at the beach with him and Elena, her best friend. Now they are both missing and Lucía only remembers a “little” argument that ended with a bottle broken on Héctor’s head, but that’s all. This complicates Simon’s life. A private investigator? No. , thank you. Simon prefers to consider himself a simple “judicial expert”. When his partner Oliver, a lawyer with financial problems due to gambling, asks him to investigate Lucía and the disappearances, Simon does not know that he is about to take the Expertise on another level. Obsessed with Bogart's film noir, Simón will go beyond all limits when he falls in love with Lucía, the amnesiac suspect in the murder he is investigating..