Few actors are more beloved than James Stewart. In rom-coms such as Vivacious Lady and The Shop Around the Corner, he is ebullient, self-effacing and effortlessly affable. In dramas such as Frank Capra’s Mr. Smith Goes to Washington and It’s a Wonderful Life, Stewart’s characters give everything in their fight for justice against the iron-gloved representatives of the State. He played good men, and by all accounts was one. But there was no room for those in Anthony Mann’s Old West. Released in 1953, The Naked Spur poured ice-cold water all over the warmth that audiences had come to expect from cinema’s most lovable everyman.

Stewart and Mann made five Westerns together. Their first came in 1950, as Winchester ’73 was set to be directed by Fritz Lang but, having felt Stewart was ill-suited to the lead role, the German master dropped out. Stewart suggested Mann as his replacement. The US director saw something in the actor that Lang didn’t, even if it would take a few films to coax it out of him.

In Jimmy Stewart: The Truth Behind the Legend, Aaron Rosenberg, producer of multiple Stewart-Mann pictures, told biographer Michael Munn that the director brought out a darkness in the actor. “It was an almost manic rage that would suddenly explode,” he said. “The audience knew Jimmy Stewart from the Capra films, and there was an element of the familiar Stewart in Winchester ’73. But there was an underlying toughness that hadn’t been seen much before.”

In 1952’s Bend of the River, Stewart’s character is a former outlaw who still bears the scars of an unsuccessful hanging. What begins as a morally ambiguous story of kinship and pioneer struggle soon metastasizes into a tale of betrayal and black-hearted revenge. Stewart’s star was darkening still.

In The Naked Spur, the “familiar Stewart” was long gone. Selfish, cynical, ill at ease, he was no longer the American everyman but the everyman’s repressed rage. Stewart plays Howard Kemp, a cowpoke tracking a criminal through the Colorado Rockies. Gun up, he approaches a greying prospector and shows him a torn poster; Ben Vandergroat is wanted for murdering a marshall in Kansas. The old man assumes Kemp is a sheriff. Kemp does nothing to correct him.

From the start, Stewart’s character is wily and unscrupulous, willing to exploit and endanger others to get what he wants – this is not the man who built Bailey Park to help people out of Mr. Potter’s slums. Before long, with the help of the prospector and a passing soldier dishonourably discharged from the Army, Kemp has Vandergroat bound by the wrists and his young charge Lina in tow.

He and Vandergroat have history, and the fugitive quickly blows his cover. Kemp is no sheriff; he’s a common bounty hunter. The soldier demands a third of the $5,000 bounty, as does the old man. Throughout the film, Vandergroat does everything he can to pit the men against each other. “Money splits better two ways than it does with three,” he says. As Kemp is needled on all sides, Stewart presents him with rattlesnake intensity – teeth gritted, fists clenched, bright eyes writ large against the blue skies of Colorado. He doesn’t trust anyone.

Producer Rosenberg, per Munn, said that Mann “liked the idea of making the audience wonder if there was something latently psychotic about the Stewart character,” and that “that theme developed over ensuing westerns, especially in The Naked Spur”. From the get-go, Stewart gives us glimpses of Kemp’s psychosis, but we don’t learn how deep his wounds are until later. After leaving his ranch to fight in the Civil War, he returned to find that his partner had sold his land, and ran away with another man. In short: Kemp was cucked.

In his essay The Collapse of Fantasy: Masculinity in the Westerns of Anthony Mann, Douglas Pye writes that “Mann’s protagonists are prisoners of a masculinity coded in hopelessly contradictory ways,” such that it creates in them a kind of “psychic split”. The terms of that division, writes Pye, are transitional. “They are presented as competing images of masculinity: on one hand, the claims of settlement, civilisation and social responsibility, and on the other of wandering, wilderness and independence.”

Kemp is this psychic split made manifest: an everyman rancher slipping into his shadow self. “It was like he was possessed,” Stewart told Munn in 1979. “He had a demon that drove him. He had a violence that was driving him mad.” To reclaim that which was stripped from him – not just his home but his manhood – Kemp must engage in the Western genre’s definitive masculine-aligned traits: anti-settlement independence, mastery of the wilderness, and unflinching violence. The Naked Spur takes place entirely in the wilds, illustrating just how far from civilisation and its good graces Kemp has strayed. Part of the reason the film works (or doesn’t) is because, for many audiences, Stewart simply isn’t meant to be hauling bodies through the Colorado Rockies; he belongs in Bedford Falls, galumphing through the snow, wishing merry Christmas to the moviehouse.

The Mann-Stewart Westerns built upon the foundations laid down by Capra in Mr. Smith… and It’s a Wonderful Life, in which a virtuous man is subjected to almost cosmic suffering. In Capra’s pictures, the hardships that trigger the “latent psychosis” of Stewart’s characters cause them to cave in on themselves: he collapses, mentally, physically or both. In Mann’s, he lashes out and drags everyone down with him.

Hitchcock was clearly paying attention. Following The Naked Spur, Hitch’s pictures with Stewart would get more and more twisted, culminating with the actor’s obsessive, corkscrew turn in Vertigo, in which the latent psychosis of James Stewart is finally brought to bear.

The conclusion to The Naked Spur threatens to be one of the ugliest in Western cinema history. With everyone but Kemp and Lina dead, Stewart’s character still has every intention of claiming his bounty and reclaiming his ranch. Lina looks horrified as Kemp, clearly deranged, hauls Vandergroat’s corpse to his horse. She begs him to stop. “He’s not dead if you take him back! He’ll never be dead for you!”

“I don’t care anything about that but money, that’s all I care about,” Kemp snaps, not quite making sense. Stewart was apparently so swept up in the character that he fumbled the line, but the garbled reading lends additional authenticity to Kemp’s instability and self-loathing. When he says, “Maybe I don’t fit your ideas of me but that’s the way I am,” Stewart might as well have been talking to his audience – “I play psychotic men now, get used to it.”

Lina makes a last-ditch attempt to appeal to Kemp, not the hardened bounty hunter but the soft, nature-loving cattleman beneath. Kemp crumbles. It was never really about the money. In the end, the only way for Kemp to move on from his past is to bury it. And so he digs a grave for Vandergroat, and for his curdled dream of recovering his masculinity.

“The pull of nihilistic isolation and the fear of commitment remain powerfully present as the film ends,” writes Pye. Indeed, the final shot is a corruption of the archetypal Western ending, in which the cowboy escapes westward to retain his independence and elude the distinctly feminine threat of domesticity. Here, Kemp and Lina make west for California and for some sort of settlement, only with Kemp broken and in no position to benefit from it. The Naked Spur ends on a backdrop blighted by dead trees, suggesting that the western myth and its heroes are also rotting.

Stewart’s wife Gloria later recalled to Munn that “Jim’s only interest in making the Anthony Mann westerns was to ‘delve into his dark side and discover if he was the actor he believed himself to be. He wanted to put miles between Mr. Smith and those anti-heroes of the Mann Westerns.’” In The Naked Spur, with dead trees at his back and nothing but hard trails ahead, he did exactly that.