Thinking of film noir, we immediately summon up the image of a hard-boiled detective in a trenchcoat wandering along a dark alley, ready to combat corruption come what may; or a group of reckless gangsters driving along the nocturnal streets of a big city, willing to risk everything for the thrill of a heist. And we think of those modern-day sirens singing in glitzy nightclubs, who use their feminine allure to seduce gullible men and draw them into an intricate web of clandestine transgressions. As Mary Ann Doane notes, because the classic femme fatale is never really what she seems, she gives voice to a threat which is not entirely legible, predictable or manageable. The danger she poses to the infallibility of the noir hero – be he on the side of the law or its rogue opposite – thus emerges as a secret which must aggressively be disclosed, while her eradication involves ‘a desperate reassertion of control on the part of the threatened male subject’. Like the ruthless gangster he combats, the tough private eye, in turn, is self-reliant and invulnerable. Playing Philip Marlowe in The Big Sleep (1946) or Sam Spade in The Maltese Falcon (1941), Humphrey Bogart, as Frank Krutnik puts it, remains ‘the manipulator of the scenario, rather than its victim’. While he may get caught up in the femme fatale's manipulations, he never fully succumbs to her fatal charm.

Although unequivocal masculine inviolability becomes rarer in the course of the 1940s, John Huston's adaptation of Dashiell Hammett's novel sets the tone for the gender trouble around which this film genre so consistently revolves. Preoccupied with the cigarette he is in the process of rolling, Sam does not initially look up when his secretary Iva enters his office, explaining that a girl named Wonderly is waiting outside to see him. Beaming radiantly, she adds, ‘you';ll want to see her anyway, she's a knock-out’.