In this gripping historical thriller, an author, on the 23rd of April while signing books, receives letters from an unknown person that shake her identity and that of her family as well as the history of her country. She embarks on an arduous search for answers about her mother, Cecilia Balaguer, who went missing in Portbou in 1960. As she digs deeper, mysteries unfold surrounding her mother’s true identity, whether she was a double agent, and the circumstances of her disappearance. This narrative invites the audience to ponder the concept of truth through multiple perspectives, engaging them in a quest that emphasizes the significance of memory in defining one's essence.