In the Other's Hair follows the lives of two young women from the first months of 1971 to the present day. On the one hand is Ramona Marquès, abandoned by a revolutionary who disappeared from her life, leaving her pregnant. On the other is Mireia Ferrer – daughter of the man who fights for the memory of deportees and founder of the association Memory and Freedom, Tomàs Ferrer – who marries Manuel, an infiltrator from the national police, from whom she has to hide to avoid scenes of domestic violence But Ramona is not content with her lot as a single mother without family in those years and decides to falsify her mother's story and create a file in the archives of the association, identifying her as a deportee, so constructing an entire life based on lies.