Go East, young missionary!

Vincent thought he could save the world, but he didn't count on falling in love.

Americans didn't invent youthful naiveté, of course, but they patented it quickly. The recipe is built right into the country's founding myths, and our canon is dominated by stories of young men striding into the world, only to find it a more complicated and compromising place than they'd anticipated.

John Dalton's thoughtful debut novel, "Heaven Lake," is a worthy descendent of that tradition. His pious young hero, Vincent Saunders, heads off to Taiwan in 1989 to convert the Asian peasants living in darkness.

His family members, soybean farmers in the Midwest, find Vincent's fervor both noble and a little extravagant. "Why the Orientals?" one uncle asks while lending him money for the two-year mission. "Aren't there congregations all over southern Illinois looking for help?" But Vincent suspects he's meant for something grander than his sparse, dawdling hometown can accommodate. He thinks he "might have the ability to see deeply into other people's lives and offer them love and wisdom they might not even have known they were seeking."

The success of "Heaven Lake" depends largely on these braided strands of sympathy and mockery drawn through the story. Too much of one and Dalton would call his objectivity into question; too much of the other and Vincent's satire-riddled body would be tossed on the heap of semiautobiographical protagonists who show up in debut novels as target practice for authors' self-hatred.

Yes, Vincent is something of a country bumpkin, "a shrewd youth," as Nathaniel Hawthorne smirked in his own treatment of this theme almost 200 years ago. He's the kind of prude who says, "I'm not the prude you think I am," thereby confirming his prudery. But if a lifetime of fervent prayer and moral discipline hasn't made him especially worldly, it has made him especially confident, which is what he needs to fly halfway around the world to open a Bible school in Toulio, a small town 20 miles from Taipei.

His first shock is discovering that Toulio is, in fact, larger and more developed than the town he left behind in Illinois. The "peasants" don't immediately see how much they need him or the light of Christ. And what's worse, he's desperately lonely. But reassured by his minister back in Taipei, Vincent begins teaching English to those willing to endure a little Bible instruction in the process. He counsels his landlord's crippled son and leads him into the comfort of the Gospels. And with the glorious example of his own purity, he tries to shame his drug-addled roommate into reformation.

None of these programs goes as planned, but the real crisis stems from an outlandishly forward young woman in his English class.

Back home, Vincent had been what Dalton calls "that rarest of things: a sexually fulfilled virgin." But in Taiwan, after months of physical and social isolation, Vincent finds the standard he upheld through college far more difficult to maintain. He knows there's no excuse - as a teacher, a Christian, and an adult - for accepting a student's persistent advances, but once he does, the rigid structure of his faith sags and snaps.

Suddenly, in the light of this sexual initiation, the straight and narrow columns into which Vincent accounted saints and sinners seem irrelevant. "He had to wonder if that talent for faith was worth anything at all, if it did nothing but lead you down a series of ever-narrowing pathways until the only real choice was collapse or more believing - fervent belief, belief of a hounded, even manic design that stormed against any contrary opinion." Having fallen into the worst cliché about lecherous missionaries, he's forced to admit, "It's a grayer, more complicated world than I ever imagined."

Just as he considers this for the first time, he's thrown out of his mission in disgrace. The plot drops so smoothly into greater and greater complexity that we barely register the shifts till Vincent is thoroughly entangled in a bizarre arrangement of commerce and desire. Discouraged and penniless, he agrees to help a wealthy Taiwanese businessman acquire a bride from China.

"Heaven Lake" never rushes, but it pulls us along with that mixture of anticipation and dread inspired by being lost in a strange place. As the story moves thousands of miles across the mainland and into the labyrinth of this scheme, Dalton demonstrates his remarkable skill at portraying the culture that Vincent finds so captivating and baffling. Old stereotypes about "inscrutable Orientals" fade into a far broader sense of inscrutable adulthood in which everything is indefinite and half glimpsed.

It's a far more nuanced treatment than "Lost in Translation," the widely praised film that showed the Japanese as unfathomably alien and soulless. Vincent finds the Asians endlessly puzzling, but his surprise always forces him to reevaluate himself and evolve from his own naiveté, rather than sink into the kind of smug depression that Bill Murray captured so well.

Of course, missionaries rarely come off looking good in fiction (or history), but this novel isn't so much anti-Christian as antipiety. With just the right touch of wit, Dalton analyzes the complex interaction of devotion and vanity, naiveté and spirituality. It's as though he's recorded the shattering of faith with a high-speed camera that allows him to play back the collapse for us, frame by frame in a captivating series of images.

The modest hope and humanity that Vincent finally clings to might look flimsy next to the shiny armor he used to wear, but in fact they're more durable and ultimately more transcendent than all his old rules. This is a story as sensitive to the complexities and beauties of China as to the territory of the human heart.

• Ron Charles is the Monitor's book editor. Send e-mail comments about the book section to Ron Charles.