The antiheroes of film noir are almost always loners. Hardboiled detectives trying to clear their name, gangsters who learned early on that no one could be trusted, a lone insurance investigator certain there's a big story underneath that mundane pile of paperwork; sure, they might have some pals here and there to do them a favor, a girl or two will come and go in their lives, but at the heart of it, they walk alone. It's a defining characteristic of the film noir cycle, so much so that even in the noirs which feature a sidekick, the poor guy is likely to be six feet under by the end of the third reel.

And that's a shame, because the few partners and sidekicks found in noir films are wholly enjoyable. They're the comic relief, audience surrogate, neutral observer and omniscient narrator all in one. Not only is a good noir sidekick familiar with all the players, they're a character who can disappear unnoticed for a few scenes then return with an important reveal. Their mere existence hints at a world beyond the frame, and at a history that begins well before the camera starts to roll. Most importantly, they provide a counterpoint to the protagonist, creating two separate but harmonious plot lines, lovely enough individually, sublime when sung together.

The term 'film noir,' coined in 1949, was never used to describe noir films during their heyday; rather, they were known as crime films, thrillers and even melodramas. Critics generally considered overt melodrama to be the domain of so-called women's films, however, and Mildred Pierce (1945), though recognized now as part of the film noir genre, was dismissed by many as nothing more than a domestic drama. This was, in part, due to the liberties Warner Bros. had taken with the James M. Cain novel on which the movie was based. Originally a hard-boiled Depression-era tale of a tough, determined woman struggling to not just survive but thrive in a world dominated by rich men, the film was updated to be a mid-40s Joan Crawford comeback, losing much of the context.

Variety, not unexpectedly, praised Ranald MacDougall's screenplay for its 'cleanup' of themes from Cain's original novel. Other critics were not so kind. Perhaps expecting more grit, or possibly suffering from an allergic reaction to the antihero being a mother rather than a gangster, Howard Barnes wrote in the New York Tribune that Mildred Pierce was so bad it was 'immensely funny,' but for all the wrong reasons. Time Magazine was more direct, complaining that the film was more like the 'waltz-time schmaltz' of popular women's author Kathleen Norris, instead of 'the fox-trot brass of James M. Cain.'

Cain's novels were frequently written from a more female perspective; not feminine, necessarily, but a world where women had far more power and agency than they tended to on the big screen. The primary female characters in his novels are fully explored, their motivations strong and, unlike in most other hardboiled books and films, clearly distinguished from the motivations of the male leads. In two of Cain's other novels, The Postman Always Rings Twice and Double Indemnity, the women are both femmes fatales and main characters, using men the same way gangsters use molls and private eyes use beautiful young heiresses.

Mildred uses men, too, but is not explicitly a femme fatale. After divorcing a lazy husband so resentful of her attentions to their eldest daughter that he took up with an older widow willing to mother him, Mildred pounds the pavement in desperate need of a job to support herself and her two daughters. Diner hostess Ida (Eve Arden) takes pity on her, offering her a waitress gig, and after months of long, hard work, Mildred has a chance to open her own restaurant, with Ida coming along as manager. Meanwhile, Mildred's home life falls apart. Her youngest, so rarely seen on the screen she seems neglected by default, dies of pneumonia, while older daughter Veda (Ann Blythe) has developed into a spoiled, snobbish brat, the kind of teenager who is equally likely to insult her mother as spend her money, all the while pursuing her mother's men.

In a typical noir, we might see an antihero and his back-stabbing love interest, usually a moll or a femme fatale; in Mildred Pierce, we instead have an anti-heroine and her back-stabbing daughter. Tough businesswoman Mildred, like so many tough businessmen in noirs before, considers her career before almost everything else, except when it's time to spoil the girl in her life. And Veda is a girl, more properly considered a fille fatale rather than femme fatale--think of that hilarious moment in the film when tiny little Veda is dwarfed by her gigantic new convertible--but she has as much experience in manipulation and deceit as a woman a decade older.

Like some of the most notable noir protagonists, Mildred also has a partner: good old Ida, her manager and friend. In the 'cleanup' of the Mildred Pierce script, the character of Ida was changed from a secondary antagonist into a noir sidekick, partly to tailor the role toward the strengths of actress Eve Arden. This did not go unappreciated upon release: the New York Times declared Arden was 'her customary hardboiled self, and that's all right with us.'

It was certainly all right with audiences, too, who relied on a comedic sidekick like Ida to give them someone to identify with, someone who wasn't completely consumed by the drama and excess. Ida sees the situation more clearly than even she knows, and is such a keen observer that she essentially acts as a narrator, albeit one that Mildred, Wally (Jack Carson) and especially upper-class twit Monte Bergeron (Zachary Scott) consistently ignore, to their own peril. In Mildred Pierce, Ida is the only person who makes a lick of sense.

Coming just at the end of World War II, as companies began refusing to hire women for any jobs not considered strictly 'women's work,' Mildred Pierce reflected the anxieties of a society in flux. Mildred, to modern eyes, may seem a determined, if misguided, businesswoman, but in 1945, she played directly into many men's distinct post-war fear that their time overseas proved they were not as necessary as believed. The sharp-tongued Ida makes the character of Mildred easier to take for audiences, by being a comedic foil that insults and gets insulted and generally appears to be a social outlier, someone who could never be a true threat.

As scholar Judith Roof explains in All About Thelma and Eve: Sidekicks and Third Wheels, Ida is not just comic relief, but a method of deliberately distracting from Mildred's breach of mid-1940s gender roles. While Mildred is getting a divorce, running her own business, buying husbands and neglecting her least favorite child, Ida deploys some of the sharpest, wittiest snark of any melodrama of the era. She's overtly masculine, unmarried, uninterested in children and complains that men only think of her as one of the boys, something unmitigated cad Wally confirms when he grouses that all women are bad news, and looking straight at Ida, he declares, 'Thank goodness you're not one.'

Above all else, Ida is loyal. Like the best of the noir sidekicks, she is protective of her boss. She spends the film trying to convince Mildred and others of Veda's duplicity, though her masculine, confirmed bachelorette status works as almost a red herring, rendering her warnings easy to ignore as more of the same unladylike behavior she's known for. Though Ida is unceremoniously dispatched from the police station after defending Mildred, there under suspicion for the murder of Monte Bergeron, she still gets off easy in comparison to other film noir sidekicks.

Take, for example, Cry Danger (1951), and the alcoholic ex-Marine sidekick by the name of Delong (Richard Erdman). Also a post-war film noir, Cry Danger concerns one Rocky Malloy (Dick Powell), a man who has spent five years in the clink for a robbery he didn't commit. Delong finally comes along verifying Rocky's alibi, but Rocky knows Delong wasn't one of the men he was out drinking with the night of the crime. Delong, sporting a hefty limp thanks to his combat wounds, confesses he lied about the alibi, hoping Rocky would part with some of the stolen cash for his help in getting him out of jail, but there's a snag: Rocky didn't commit the crime. Delong hangs around town, even bunking with Rocky as he makes his rather hardboiled inquiries amongst the local criminal element, looking for the real robbers and demanding some of the stolen cash as compensation.

Delong as a character, somewhat strangely, has very little reason to stick around. He's provided his obvious narrative function -- the alibi needed to get Rocky out of jail -- and the character could have easily disappeared afterward without affecting the film. Delong never tags along with Malloy, and in fact possesses no investigative skills whatsoever. He is not a man for clever ideas or quick solutions. His days are spent drinking, laying around a rented trailer and hoping to get a date with his neighbor, a cute blonde pickpocket. As a sidekick, he is pretty worthless.

As an indicator of the kind of world Rocky Malloy inhabits, however, Delong is invaluable. Just as one of Dick Powell's earliest films, Gold Diggers of 1933, featured a song about forgotten World War I veterans, this Powell film nearly two decades later makes sharp sociocultural commentary on the struggle of soldiers returning from World War II. Delong, the only survivor from his company of Marines, is adrift in a culture which has few opportunities for a man with both physical and psychological wounds that have not fully healed. He relies on scams and near-criminals like Rocky to survive, and is happy to be a true pal, the one person our noir antihero can trust, but it's a perilous existence; like so many other sidekicks, Delong finds himself the victim of a heinous attack meant for his ersatz boss, Rocky.

Loyal though he is Delong has nothing on the desperate devotion Jeff Hartnett (Van Heflin) has for his boss in Johnny Eager (1941). As alcoholic as Delong and twice as troubled, Harnett is also a character meant for pointed sociocultural commentary. He's a smart guy, possessing not just street smarts but book smarts, his speech all flowery quotations and complicated metaphors. But he's stuck in this little vocational hell, reliant on his corrupt crime boss Johnny Eager (Robert Taylor) to survive. It's not about breaking the law with Harnett; he's heartsick over Johnny's unmitigated streak of cruelty, a constant lack of empathy and ethics; not only can Hartnett not stop it, he relies on it, otherwise he wouldn't even have the clothes on his back.

As Johnny Eager opens, we see the plucky young Eager working hard as a cab driver, making good with his probation officer and promising to fly the straight and narrow from now on. Soon, we discover it was all just a ruse: he's still secretly in charge of a large criminal enterprise, and wants to go slightly legit by opening a dog racing track. But local bigwig prosecutor John Benson Farrell (Edward Arnold) is on to Eager and vows to stop him. When Farrell's beautiful young daughter Lisbeth (Lana Turner) falls in love with Eager, he takes advantage of the situation, making her believe she's killed a gangster in self defense, using this secret as a bargaining chip to blackmail Farrell into allowing the race track to be built.

Johnny Eager is a film that immediately announces itself as wedded to the standard three-act structure, often turgid despite its hip, rapid-fire dialogue. It's a standard noir with a rough antihero and love interest subplot, plus a storyline that is difficult to suspend your disbelief for. But then Jeff Hartnett arrives, signaling a welcome tonal change in the film, something the filmmakers clearly knew. They introduce not one but two potential sidekicks for Eager early in the film, red herrings to distract the audience, keeping them complacent as they gently wonder who Johnny's real pals are.

When Hartnett slurs his way into the film, the complacency disappears. He is a sidekick who changes the context of everything that has happened in the film up until that point. His immediate contempt and disinterest toward Eager's lowbrow, thuggish ways immediately mirrors the audience's own. The irritation you've been feeling toward Eager for being such a stereotype allies you with Hartnett, a character who doesn't have any more time for these tired tropes than you do. And the counterpoint provided by this drunken, sad and stifled man with a brain going to waste illuminates Eager's true character. He's no longer the cool, slick, matinee-idol antihero he began the film as, but a full-fledged psychopath. With the arrival of Hartnett, someone -- finally -- is properly horrified by a cinematic gangster, showing not usual detached concern but actual panic and despair.

By the time the perversely Byronesque Hartnett punctures the obligatory psychological undertones of film noir with a sarcastic, 'Mr. Freud, take a letter,' the character has turned the entire genre on its ear. His love for Johnny is genuine and mature, not the snickering subtext of so many other noirs just trying to get one past the censors; his stumbling around like Frankenstein's monster is no cheap callback either, but a shocking expression of his thwarted humanity. That the only man who could make such a plea for basic human goodness is both gin-soaked and pathetic only highlights the limitations within the genre, and became director Mervyn LeRoy's indirect but unmistakable challenge to future noir films.

In a genre populated by loners and outcasts, creating a partner for the protagonist was a tricky balancing act, but often proved to be both an invaluable narrative assist and a true audience pleaser. While the impossibly stylized idols of the silver screen got the lead roles and the attention, the sidekicks of film noir brought real texture to the genre. The Jeff Hartnetts, Idas and Delongs were the cinematic manifestations of real world cultural issues, bearers in the film noir genre of both consciences and dreams.

When not watching classic movies, Stacia Kissick Jones is writing about them, dreaming about them or complaining about them. Her ruminations are there for all to see at She Blogged by Night.