The Narrow Margin is a tight, economical thriller which constricts its action almost entirely to a train. The hard-boiled, snub-nosed police detective Brown (Charles McGraw) is enlisted along with his partner to pick up the widow (Marie Windsor) of murdered gangster Frankie Neall, escorting her from Chicago to Los Angeles through a likely hail of bullets in order to testify before a grand jury about her husband's former colleagues. Brown's partner doesn't make it to the train, which leaves the detective cooped up alone in tight spaces with the feisty Mrs. Neall, while the mob's thugs and assassins gather their forces to prevent her from ever making it to L.A. It's a perfect set-up, a recipe for claustrophobic action and teeth-gritting suspense, and even if the plotting sometimes fall short of its promise, director Richard Fleischer rises to the occasion to deliver one of the great B-movies.
The tight setting prevents Fleischer from applying most of the usual noir touches. A few early scenes, when the detectives first pick up Mrs. Neall at her Chicago apartment, take place in dense shadows with expressive lighting, but once the action shifts to the train the sets are brightly lit and confined, with no room for the large areas of light and shadow that form the visual language of so many classic noirs. Fleischer fully exploits the limitations of space inherent in his story, emphasizing the cramped quarters both for suspense and touches of light comedy. The latter is present in the colorful bystanders who provide some momentary distractions from the otherwise relentless plot: the distinctly non-jolly fat man (Paul Maxey) who keeps blocking the passage for both cops and mobsters, and the little boy who mistakes Brown for a train robber. Even these diversions are tied into the central story soon enough, but Fleischer has less interest in comic relief than he does in getting the most, visually, out of his limited sets. He works with the train's tight corridors as much as possible. Characters are constantly having to squeeze past each other or duck into side rooms, which inevitably expand the action into new areas. The film has an exquisite sense of spatial relations. Much of the action takes place along straight lines, with Brown and the trio of mob assassins dodging each other as they weave up and down the train's corridors in repetitive patterns. The action is built on cyclic journeys between the dining car and Brown's quarters, with the detective executing clever ploys to outfox and delay his enemies. It's absolutely crucial, to get the most out of Brown's maneuvering, that the audience get a sense of where the detective is going at all times, and Fleischer is careful to keep the geography precise.
But even as he builds up the claustrophobic intensity of the tight spaces, Fleischer is simultaneously working to expand the spaces available to him. To this end, he makes excellent use of the windows of the train, which at various times and in different lighting function as either actual windows or as mirrors. Much is made of the conceit of spying through windows, as Brown's primary pursuer Kemp (David Clarke) makes it into a semi-open game of wits between cop and mobster. The two are continually glimpsing each other through windows and in reflections. In the dining car, Brown sets himself up so he can see Kemp mirrored in a reflective window pane, while on stops Kemp spies through windows from outside the train, to the point that seeing the mobster framed by a window becomes a marker of trouble and suspense. After Kemp has misidentified the innocent passenger Ann Sinclair (Jacqueline White) as Neall's wife because of her developing friendship with Brown, he stares at her through the dining car window, twisting his face into a sinister leer as he lights a cigarette. At the film's climax, the reflective quality of the train windows plays an important part in the denouement. This is foreshadowed in a scene immediately before the final showdown: a closeup on Ms. Sinclair, her face framed against a dark train window, with a slumping, shadowy Brown reflected in the window, looking like a boxer getting ready for another brawl. Fleischer's use of the train windows continually expands and opens up the areas available to him, and he makes especially ingenious use of them in building suspense in the film's final act. As the train races along and the various pieces of the puzzle begin to fall into place, a mysterious car begins keeping pace with the train, first glimpsed outside the window over Brown's shoulder as he gets up from the dining car, and returning several times in the background. It becomes obvious that the car is following the train and is probably linked to the mobsters, and Fleischer begins both cutting to it directly and allowing it to appear naturally outside the windows; its very presence becomes a foreboding signifier of the approaching end.
If Fleischer's able direction is the film's primary asset, he's definitely assisted by the tough, uncompromising central performance from Charles McGraw. McGraw's square-jawed cop is a well of conflicting emotions, all of them hard and seething. He's principled, but maybe not entirely stolid. When the mobsters offer him large payoffs to look the other way, he rejects their offers, but he obviously at least gives it a thought. He's uncorrupted, but not incorruptible, and he's got a real streak of brutality and anger in addition to his wise-cracking wit and quick-thinking intelligence. When he finally corners Kemp, the fight between the two men is crisp, rough, and physical. Fleischer shoots much of it in closeups and tight two-shots that draw attention to the small space the men are fighting in and the violence of their blows. The effect is heightened even further when Brown conducts a threatening interrogation after the fight, and Fleischer shoots it entirely in extreme closeups, at first keeping the two men separate in shot/counter-shot patterns and then thrusting them together as Brown grabs the other man and pulls him close to make him talk. McGraw's Brown is not a typical movie cop, he's a brawler and a tough guy, and when he says that he'll track down Kemp and kill him if the gangster doesn't come clean, it's a credible threat. Fleischer really knows how to film his star, letting the shadows etch hard lines into McGraw's twisted expression in this scene in calmer moments, the actor looks the part of the clean-cut good guy, and the tension between the two sides of his character serve the film well.
McGraw's persona also plays off of his villainous foils in interesting ways. Kemp is a memorable and vibrant small-time hood, with his beady-eyed leer, loud suit, and ratty mustache. Even more intriguing is Yost (Peter Brocco, uncredited because of the blacklist), a blandly menacing figure posing as a businessman and offering Brown the temptation of a hefty bribe. Yost's lizard-like charm and nagging insistence, like a dark conscience, form an excellent counterpoint to Kemp's more obvious villainy. It's a shame when the film unceremoniously drops him with some puzzling exposition: someone casually mentions that he got off the train on a stop, and that's it for him. The final villain in the trio is Densel (Peter Virgo), the killer who shot Brown's partner, and who catches up with the train late in the film. The plot calls for his appearance to have some impact that it never does. Throughout the film, he's known as the man with the fur-collared coat, a key detail pointed out in the earlier scene that makes it a sure thing that he'll reappear later. But when he finally shows up, he's only around long enough for a perfunctory scene or two, never developing the personality of the other two hoods, and surprisingly nothing is made of the fact that he killed Brown's friend and partner. The dramatic tension that should have infused his appearance simply fizzles away instead.
Curiously enough, the film also seems to have little narrative interest in developing the character of Mrs. Neall. She and Brown have some stock interplay, exchanging sharp dialogue, but it seems rote there's so obviously no chemistry between the pair that the noir wisecracking can't amount to much. Marie Windsor does her best anyway, spending most of the film cramped up in one tiny room, lounging around in lacy black lingerie and occasionally poking her head out the door to unleash some fierce femme fatale attitude. For the most part, Fleischer seems more interested in tracking the progress of Brown and the thugs through the halls of the train, than in spending much time with the ostensible target of all this fuss herself. A few final-act twists render her even more irrelevant, and the film finally dispenses with her altogether. Fleischer does give her one of the film's best moments before she goes, but it has little to do with the script or Windsor's performance, and everything to do with the way he highlights the tiny gesture of a hand sweeping across a phonograph to start its record playing.
Despite the slackness and inconsistency of its narrative, The Narrow Margin remains a first-rate thriller for McGraw's brilliant performance and the frequent ingenuity of its direction. Richard Fleischer propels the film well above its origins, ignoring the lame twists of the final act and the many loose threads left hanging in its unsatisfying resolution. Its narrative holes are evidence of the film's B-movie status, but the many flashes of Fleischer's crisp visual storytelling are continual reminders of just how much verve, intelligence, and invention can energize even the most crippled of B-thriller scripts.