Film noir films from the 1940s and 1950s reflected post-war societal fears and paranoia through their themes of distrust, loss of innocence, and despair. These films used stylistic conventions like voiceovers, low-key lighting, and nonlinear narratives to portray cynical protagonists and femme fatales who often brought the protagonists to their downfall through manipulation and betrayal. Within the genre, corrupt cops added to the constant theme of paranoia, while the settings, costumes, and iconography reinforced the dark and hostile tone through elements like dark streets, flashing neon signs, and trench coats.