ट्रिविया

When Commissioner Ruiz enters Claus' apartment, a poster dedicated to the poet Antonio Machado can be seen on the wall. Considering that Machado was a declared partisan of the Republic, died in exile in the early days of the Spanish civil war, this poster can be considered as a clear progressive nod that should have gone unnoticed by the Franco censorship in 1965.

Among the possessions of Claus that Commissioner Ruiz finds when registering his apartment there is a book about Hitchcock, which is an ironic wink of the scriptwriters since the style of this film is clearly inspired by the suspense of Sir Alfred Hitchcock's movies.

Hanging on the wall of Claus's apartment is a huge reproduction of Picasso's 'Guernica'. Considering that Picasso was a strong detractor of the Franco dictatorship and that this painting was created to denounce a massacre committed by Nazi aviation during the Spanish Civil War, to show it on screen was undoubtedly a great daring in a film shot in 1965.