My streaming gem: why you should watch Detour

The lady is a wrecking ball. Has there ever been a performance with the same bite-force per minute of screen time as Ann Savage in the 1945 film noir Detour? She appears at an Arizona gas station – hands on hips, not-gone-to-bed eyes, sour mouth, hair mussed by the desert wind – just over half an hour in. When our fedora’d hero offers her a ride, she is already sizing him up as she walks over with her suitcase. In 35 hot minutes, she will have humiliated him, destroyed his relationship, hung another murder on his tab, and have him ruefully signing off: “Fate, or some mysterious force, can put the finger on you or me for no good reason at all.”

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Wim Wenders called Savage’s a performance 30 years ahead of its time. Maybe that’s pushing it, but even with all the femme fatales on the roads in 1945, there wasn’t much like it. Al Roberts, the drifter played by Tom Neal, is taking it easy behind the wheel, his new hitchhiker Vera asleep in the passenger seat, when her eyes flick open: “Where d’ya leave his body?” She knows: that the car belongs to one Haskell, who picked up Al a few miles back, before suffering an unlikely heart attack.

And now Al knows where Haskell got the scratches on his hand; she was the hitcher the dead man threw out before him. Never blinking, voice metallic, her accusations come like knife thrusts. “Shut up! You’re a cheap crook and you killed him!” “Act wise and you’ll pop into jail so fast, it’ll give you the bends.” Worst of all: “You’re making noises just like a husband.”

This is more femme frontal than fatale. Compare it to Savage’s work in Apology for Murder, from the same year, a knock-off so obvious of Double Indemnity it was supposed to be called Single Indemnity. Savage works hard as a velvety seducer firmly in the Stanwyck mould, but she is something else in Detour. The level of, well, savagery is so great that not only it does it flout studio notions of “starlets”, it tears up the conventions of the femme fatale before the conventions had had time to form. Even Vera’s attempt to seduce Al is brazenly cynical – and not in the glamorous way that gets the audience wishing.

Look closely at her and there’s desperation: the deathly lack of hesitation about her money-making ploys; a cough that is a suggestion of TB; the only softness in her already spoilt by self-pity. It’s not an act, like the classic femme fatales; it’s an animalistic bid for survival. Detour seems to stand as much on the blasted plains of Depression-era America as behind the postwar Venetian blinds of noir. Savage’s jagged, slightly expressionist performance belongs in a horror movie – one called real-life.

It’s the kind of impact a 67-minute movie needs. Classic noir is always best when it doesn’t hang around, with bullethole titles to match: Pitfall, Crossfire, DOA etc. Detour – made by Poverty Row outfit PRC – didn’t have much choice. Director Edgar G Ulmer, a Nazi escapee like many directors of noir, said he banged it out in six days for just $20,000. It seems, like Al, he may have been something of an unreliable narrator. Recent research shows the shooting schedule was actually a month, costing $100,000 (Ulmer also claimed, back in Germany, to have worked on Der Golem, Metropolis and M, of which there is no proof). It was still bare-bones stuff, though. There are essentially just four locations: the Break O’ Dawn, the New York nightclub in which Al plays piano; a last-chance diner; the hotel room Vera locks him in; and lots of rear-projected car journeys. Ulmer apparently threw away much of the shooting script. What emerged from all this compression was a high-proof distillation of the genre with a hell of an after-kick.

Nowhere is that more apparent than with Neal, the ostensibly junior partner in Detour. With his purdy doe’s mouth, he is constantly complaining, weak, a pushover for the likes of Vera. But can he be trusted? He indulges in a torrent of world-weary voiceover, par for the noir course. It’s not clear this bad habit should be taken at face value; as he says to Vera: “I’m just thinking out loud”, and as she retorts: “People get in trouble for doing that.” Even if his account of Haskell’s “heart attack” is true, there is something self-condemning about how easily he assumes other people – including the police – will think the worst. Either his worldview is already filled with some obscure guilt – or, like Vera suspects, he has good reason to feel guilty. We’re never quite sure about Al from that moment, or about anything else he has to tell us later.

That instability – that unknowable subjective centre so crucial to noir – is how Detour still maintains an unbreakable clasp. The uncertainty is somehow scrawled into the film’s cheap fabric, the unreal rear projection, the roughness of its telling. It’s not surprising this B-movie quickie became an ur-text for noir. Starting to get its dues in the 1970s, it lingered on like a hastily uttered curse. Neal was convicted for the manslaughter of his wife in 1965; a kind of uncomfortably close-to-home PR that probably didn’t do the film’s reputation any harm. His son, Tom Neal Jr, starred in one movie: a 1992 remake of Detour, as Al Roberts. It seems unlikely Detour will thumb a third ride.

• Detour is streaming on Amazon Prime in the US and UK