Inspired by a novel, Professor Unai Eguía begins investigating the mysterious disappearance of a Catalan Republican. At the same time, Antón Gandarias sets out to uncover the truth about his uncle, who never returned from World War II. Archives, letters, and memories lead both men to Prague, where their investigations unexpectedly converge. There, they uncover a hidden chapter of the war: the silent resistance of a crematorium director and his son. What begins as a personal investigation transforms into a journey into the depths of deportation, loss, and responsibility.