As far as B-movies go, you cannot do much better than Edgar G. Ulmer's 1945 Detour, a film that is so pared-down as to be almost elemental. The most significant aspect of the movie is the lead performance by Ann Savage as the femme fatale, Vera. As Roger Ebert, "There is not a single fleeting shred of tenderness or humanity" to her personality. Before Savage's entrance into the film at about the halfway mark, Detour is like its protagonist, Al (Tom Neal)—it wallows in its murkiness, waiting until something (or someone) with some life to spark it. Vera does precisely that: she simply sets the film on fire.
Let me back up a bit. The story is about Al, a down-on-his-luck musician whose girlfriend, Sue (Claudia Drake) leaves their club in New York to try to make it in Hollywood as an actress. With nothing else to live for, Al packs up what little he has and attempts to hitchhike cross-country in order to be reunited with his girl. On the way, he encounters millionaire, Haskell (Edmund MacDonald), whose scars and bizarre conversation mark him as an odd ball. He dies of a heart attack, and Al assumes his identity in order to avoid the police. By chance, he picks up a fellow hitcher, Vera, who happens to know Haskell and promptly figures out Al's ruse. She holds him hostage until they can figure out a way to access Haskell's big bucks and split them down the middle.
Al, as played by Tom Neal, is a complete stick in the mud. His constant narration throughout the film taps the depths of his self-pity and neediness, which is also shown by his near-umbilical attachment to the women in his life. In every sense of the word, Al is a sad sack. So when Vera shows up and turns his life further upside-down, that's when the movie really begins. The first shot of her lingering and leering: it pulls back slightly to reveal her lithe form gathered in a tight skirt and sweater. There are dark bags under her eyes, which are bereft of life. For the first moments of her performance, she is silent, looking vaguely ahead with a thousand-yard stare. But in very little time, it becomes apparent that there is much more to Vera than her pretty looks, which Al describes as "too natural" to be beautiful. How right you are, Al.
Once Vera cottons on to Al's scheme, their relationship takes on a character that reminds me of a more menacing version of the interplay between William Holden and Gloria Swanson in Sunset Blvd. Like Jack Gillis, there is a masochism in Al's character: although he could rather easily escape from the boozy Vera, he stays because on his own, he'd evaporate into thin air. But unlike Norma Desmond, Vera has a firm grasp on reality: she understands the power she has over Al, and willingly exploits it every chance she gets. Consider the moment when Al and Vera must spend their first night together in a hotel as "husband and wife." Vera knows full well that she could get away with whatever she wants, and subtly attempts to seduce her prisoner: "I'm going to bed, now." Although Vera tries to seem like she wants Al, she's like a female praying mantis: she only would have sex with Al for the opportunity to bite his head off afterward. Al resists because of his bland fidelity to Sue, not because he actually has any willpower.
Detour, due to its shoestring budget and awful production values, has no business lasting as long as it has. The other great noir directors—John Huston, Orson Welles, Otto Preminger—were recognized for their talent and rewarded with stars like Humphrey Bogart and big bucks. Ulmer's film is a testament to how a perfect storm of talent, resourcefulness, and artistry can overcome humble origins. All the pieces fit snugly together in Detour, but if you took any of them away, they'd fall apart.