This paper focuses on the comparative analysis of the film La ciudad perdida (The Lost City, Margarita Alexandre and Rafael Torrecilla, 1955) and the novel of the same title (Mercedes Formica, 1951), in which the film is inspired. The study starts with a historical approach aiming at contextualising the proposed case study in the context of the Spanish film production which - from the late 1940's onwards (with the early exception of Rojo y negro -Red and Black, Carlos Arevalo, 1942)-, starts to elaborate narratives of the Spanish Civil War that seem to elude the myth of the crusade and consider instead the confrontation in terms of fratricidal conflict. Then, formal and thematic analysis of both the film and the novel are carried out, specially considering the representation of the city of Madrid as an hypothetical space for the inscription of the vanquished of the Spanish Civil War, according with new cultural discourses pointing out to a redefinition of the enemy which blurs its alien nature, over which insisted the early post-war public discourses and cultural production. Last, and considering the uneven fate, and conflicts with censorship suffered by the novel and the film, this paper reflects on the achievements and limitations linked to the early discursive spaces of reconciliation emerging in the Spanish literature and cinema of the 1950's.