Starring Naomi Watts and Edward Norton. Rated PG.

What makes a marriage? That’s the principal and quietly profound question behind The Painted Veil, based on W. Somerset Maugham’s book of the same name. Despite the tale’s majestic scope, taking in Chinese politics, modern science, and British colonialism in the 1920s, it maintains its intimate focus on the relationship that slowly evolves between two people ill-suited to each other.

Those two are Kitty (Naomi Watts), a spoiled London socialite, and Walter (Edward Norton), a dedicated biologist who is inept at communicating things that have nothing to with medicine. Eager to get away from her parents, she agrees to marry the newly met Walter, even though he is soon off to a government lab in Shanghai. Their sense of a shared adventure quickly fades when they fail to connect sexually, emotionally, or even through basic interests. Of course, this isn’t helped by her torrid affair with a married diplomat (Liev Schreiber).

When timid Walter finally figures things out, he hands her a cruel choice: be divorced in a messy public scandal or accompany him to remote Guangxi province, which is being decimated by a cholera epidemic. Kitty finds his ultimatum “monstrous” and, indeed, her new husband is as absolute in hatred as he was in his unexamined love for her. What they find when they arrive, beside natural beauty, is mounting numbers of dying people and a hotbed of Chinese politics, as represented by Waddington (Infamous’s Toby Jones), a colonial officer gone native, and the sophisticated Colonel Yu (masterfully underplayed by Anthony Wong Chau-Sang, of the Infernal Affairs movies), an honest nationalist adept at playing all sides.

Initially, Walter uses the depredations of the place to punish his errant wife. But as he throws himself into the work of saving lives, she begins reassessing hers, especially after she offers her services to a Catholic mother superior (Diana Rigg) who turns out to be surprisingly candid about the connection between religion and marriage.

That last bit is pure Maugham, who managed to find a balance between mysticism and the mundane that presaged the Beats of the ’50s and the counterculture that followed. The Veil has been lifted twice before, in a 1934 glamour vehicle for Greta Garbo (during the same year Maugham’s Of Human Bondage was filmed), and renamed The Seventh Sin in 1957, with Eleanor Parker in the lead.

The new version, coproduced by Watts and Norton—who turn in some of their strongest work to date—has the advantage of being filmed in China, by The Piano DOP Stuart Dryburgh, in this rare coproduction with the United States. The direction from John Curran, who handled Watts well in We Don’t Live Here Anymore, never hits a wrong note, while the thoughtful script, from Ron Nyswaner (Philadelphia, Mrs. Soffel) weaves together the many elements without bloating the tale. You could say it’s a marriage of smooth storytelling and deeper personal truths. And it’s one that works.