IOWA CITY - If you want to understand how different Marilynne Robinson is from other contemporary novelists, all you need to do is walk into her dining room.

"These are my favorite books in here," says the author of "Housekeeping," "Gilead" and last month's "Home" as she motions toward the bookcase that fills one end of the small space. "See, look: Calvin, Calvin, Calvin."

Sure enough, here are the multivolume "Commentaries" of the 16th-century Protestant theologian.

Here are the two volumes of Calvin's "Institutes of the Christian Religion," without which Robinson thinks you can't understand Herman Melville. Surrounding these are a multitude of other theological and educational works, few less than a century old.

"Look at this," she says, flipping through the pages of a densely illustrated family Bible picked up in an antiques store. She points to a clutch of McGuffey Readers, then to "one of my treasures," a 19th-century biographical encyclopedia filled with "people that have dropped out of history."

There's not a modern novel in sight, though if you were to wander into the living room, you'd find a few on the coffee table.

Robinson hasn't read them. "I'm always reading all this other crazy stuff."

Appearances here - as with Robinson's but deeply original fiction - are deceiving. A tall woman of 64, she curls forward on the living room couch, an unusually calm poodle at her side. She smiles often and laughs easily, frequently at her own expense.

She's asked about the relative importance in her work of voice and character, as opposed to plot.

"Plot. Not a word I use," she says. "Some people think it's not a concept I have."

This is not entirely true. She managed to work suicide, a train wreck, adolescent rebellion and a climactic fire into "Housekeeping," the now-classic novel that introduced her in 1981, though to list the elements that way is to misrepresent the book's eerie quietness.

And in "Gilead," the Pulitzer Prize-winning second novel Robinson published in 2004, she grafted a violent branch of the 19th-century conflict over slavery onto what was otherwise a small-town story set in the 1950s.

"Robinson's words have a spiritual force that's very rare in contemporary fiction," wrote James Wood in The New York Times.

Her new book, a finalist for the National Book Award, is set in precisely the same time and locale as "Gilead." It revisits characters the author found herself unwilling to give up. With different people's stories moved to center stage, "Home" manages to be both intertwined with its predecessor and a work that stands alone.

Try to imagine another 21st-century writer beginning a crucial scene in each of two novels by having a character say: "Reverend Ames, I'd like to know your views on the doctrine of predestination."

"I think that's a very thorny problem!" Robinson says, and laughs.

In Christian theology, predestination is the idea that God has foreordained all human fates, including damnation and salvation. The obvious problem with it is that it undermines the concept of free will. But "the problem with any other construct," as Robinson explains, "is that it limits the power of God."

No easy answers here - and never mind the difficulty of making compelling fiction out of theological argument. Which somehow Robinson does.

The Rev. John Ames, a Congregational minister, is the narrator of "Gilead." The man who asks the predestination question is Jack Boughton, the wayward, drunken son of Ames's closest friend.

Jack's lifelong alienation from his devout parents and good-citizen siblings, all of whom love him dearly, dominates the narrative in "Home." At the time he asks his question, he has returned after a 20-year absence: worn, guilt-ridden, desperate for redemption.

But Robinson's novel is also the story of Jack's quiet sister, Glory, herself returned home after "failing to take hold in the world." Seemingly invisible to Ames and her own father, she may be the strongest character in the book.

In Idaho, where her father worked for a lumber company, Robinson and her brother used to sleep sometimes on an open porch at her grandparents' house, where "there was nothing around us but mountains and woods. Nothing. No other sound, no other light, nothing.

"The way that mountains sound in a wind, you know, it's impossible not to feel that you are surrounded by deeply living things."

In college at Pembroke, a roommate dared her to take a writing class from postmodernist John Hawkes. "She did me a big favor," Robinson says, because Hawkes proved an encouraging reader of her distinctly pre-modern writing.

She flirted with the idea of divinity school. But to a woman, in those days, that looked like "the royal road to marginalization," so she stuck to literature.

"I wrote 'Housekeeping' thinking that I was writing an unpublishable book, and that gave me an enormous amount of latitude," she says. "And I was just interested in things like what can you do with an extended metaphor, you know?"

She wanted to "step outside what seemed to me to be the conventional language and the conventional posture of contemporary books." She wrote from the landscape she knew, where "I could make weather and vegetation and so on into my own dialect."

There wouldn't be another Robinson novel for 23 years. There was motherhood, a divorce, a steady job. (In 1989, Robinson accepted a teaching position at the Iowa Writers Workshop. She's still there.) And there were two nonfiction books.

Living for a time in England, she found herself "angry to the depths of my soul" to learn that a nuclear complex there had turned the Irish Sea into a dumping ground for plutonium. In "Mother Country," she asked how this came to be.

In "The Death of Adam: Essays on Modern Thought," Robinson undertook to refute the caricature of Calvin as a gloomy, intolerant fanatic.

And having found a unique voice for "Housekeeping," she had trouble escaping it. Her solution was to read herself out of modernity.

"I read about the Albigensians, everything in the world," she says, referring to a persecuted sect in medieval France, "simply to create another sort of ecology in my brain." After moving to Iowa, she started reading about the Midwest. "I can't stand to be in a place that I don't feel I know a history about," she says.

One day, while writing something she wasn't happy with, she found herself channeling an old minister. Finally, she had a novel on her hands. She set it in a town she called Gilead - a southwest Iowa community with a buried, fiery past.

In "Gilead" she created a fictional version of Todd, Iowa, a hotbed of abolitionism and a stop on the underground railroad.

"Home," by contrast, seems more focused on individual human frailty of the kind personified by Jack Boughton, with his fear that damnation, for him, might be predestined.

Yet here's where what she calls Todd's lost "archaeology of radicalism" comes in. Jack has fathered a child with a black woman he truly loves. He rests his fading hopes on reconnecting with them. But the specifics would so disturb his lfather - a classic 1950s Northern racist - that Jack can't confide in him.

"Oh, it's terrible to interpret your own writing," she says. "If Jack could come home and be home, it would mean that in a certain way he would have experienced a restoration of himself," Robinson says. Instead, "this mythic home for him is one that excludes his own family."