As with Howard Hawks' masterpiece, Shanghai Express (written by future Big Sleep screenwriter with uncredited help from Hawks himself) opens in an exotic location so bustling with activity that its exoticism is defined less by the setting than the menagerie of people wading through it. A cast of characters from different nationalities and temperaments get their train tickets and fight through the crowds to get on-board before departure. Terse, meaty dialog exchanged between people dances around sexual lines without leaving much to the imagination, as the presence of certain kinds of women set some passengers on edge and generate intense excitement for the rest.
One of those women is Shanghai Lily (Dietrich), a "coaster" whose reputation precedes her. When word gets out that she may be on the train, most of the men can scarcely contain their lust, and even the perpetually offended missionary sounds, at the very least, intrigued. But when a British military doctor, Captain Harvey (Clive Brook), stumbles across the be-boaed, veiled minx, he recognizes Lily as Magdalen. Dietrich's hard features do not react to this unexpected reunion, though even her wry smirk cannot fully mask the shock of seeing this man again, much less being called her old name.
The heated lines passed between Harvey and Lily reveal a broken romance spurned by her actions, a loyalty test that backfired and drove the doctor away in offense. But to look at Lily now, the thought of her being so sentimental as to try her lover's dedication is almost incomprehensible. Her flippant, seductive tone of voice carries through the entire film, even at her most honest and selfless. Dietrich displays here a singular ability to be unmistakably human and sentimental without betraying an ounce of softness. To the audience, Lily's lingering love for Harvey is impossible to miss, but she's so hard and unflinching even under her already imposing exterior that one can forgive the doctor for not seeing her true feelings.
This burial of melodramatic, theatrical emotion under layers of carefully ordered, objectively removed dressing meshes beautifully with von Sternberg's camera style. Shanghai Express, made during the gritty punchiness of the Pre-Code era, reflects that time period in its punchy dialog and indirectly direct sex talk, but the director's visual elegance far outstrips his peers. Like any great train movie, Shanghai Express generates a constantly shifting backdrop organized by rigidly static, even claustrophobically narrow and unchanging, mise-en-scène. Chiaroscuro lighting casts what would otherwise be a romantic drama as a borderline thriller of moral ambiguity and hidden despair, a pre-noir underworld of false fronts and swift judgments. The world outside the train is an ever-changing nightmare of building tensions, steam swirling around silhouetted railroad workers and a gradually mounting rebel presence that slowly encroaches on the already unstable peace among the eclectic passengers.
The danger finally mounts to the point that it penetrates the insular realm of the train, and von Sternberg's alteration of lighting and shot placements completely change the tone of the familiar interior sets. Character dynamics also get overhauled, with the revelation of a rebel among the passengers and reevaluations of people by the others. The other courtesan traveling on board, played by a fierce Anna May Wong, becomes intense with patriotic fervor when she realizes Chang is the wanted warlord, speaking coldly of his offenses to China. The judgmental missionary who refused to even sit in a cabin with these loose women comes to view Lily in a different light, and he even finds himself defending her to the others when the gossipy nature of the other passengers boils over.
But the act that turns the missionary's opinion of Lily is not so much a different side of the woman so much as the first good glance of her real self. She nearly sacrifices herself for Harvey, who is still so adamantly clueless that he does not realize what he gets himself into by disrespecting the warlord and how brave Lily is to volunteer her services to save her true love. The tragedy of his ignorant dismissal endures even past the seeming resolution of the perilous situation, as Lily makes plain her love for Harvey while not delving into the full extent of her sacrifice, at this point unable to be open with herself, much less others. A flippant Harvey notes that Lily is trembling when they talk after being rescued from Chang, to which she says, "It's because you...touched me, Doc." Dietrich utters this response with a tossed-off, even playful bite, a come-hither tease that permits her to openly state how she feels while still hiding behind her armor. But when von Sternberg frames Dietrich in a highly stylized, shadowed medium close-up after she leaves his cabin, leaning against the door and trembling so violently she can barely get her cigarette to her lips, the full extent of her devastation engulfs the screen.
Shanghai Express ends on conventional terms in a general sense, but there is a surprisingly modern willingness to accept one's partner for who they are, as opposed to what one wishes the other should be. Refreshingly, Shanghai Express is not about the redemption of a whore; in fact, the two most heroic people in the movie are both courtesans and both act out their bravery through their seductive powers. But the real delight remains that train ride, so locked into its path—in physical and literary terms—yet so routinely reinventing and fresh. I cannot think of a train movie to rival it until Wes Anderson made his even more ruminative The Darjeeling Limited, another film that dismantles preconceived notions of people as privileged whites ride through a troubled, foreign, complex land. And Shanghai Express doesn't even have such lofty ambitions; it primarily serves to show off von Sternberg's formal skill and Dietrich's unique acting chops. But as they say, when you've got it, flaunt it.