Book groups have been a popular plot device in commercial fiction. It’s a handy way to get a group of people together, and they’ll always have something to talk about. Given the high-toned volumes and literary discussions featured in such bestsellers as “The Guernsey Literary and Potato Peel Pie Society” and “The Jane Austen Book Club,” it’s an amusing change of pace to meet a book group member like Ava, the protagonist of Ann Hood’s new novel. Instead of bothering to read “Pride and Prejudice,” she guiltily watches the movie with Keira Knightley. Granted, she has an excuse; she’s still reeling from being dumped by her husband, and Austen’s famous first sentence (“It is a truth universally acknowledged,” etc., etc.) prompts Ava to groan, “Was everything about marriage?”

It seems odd that someone whose mother owned a bookstore would have so little appetite for reading, until we learn that the other great trauma in Ava’s life was the accidental death of her sister Lily and her mother’s suicide a year later.

Ava blames herself. She was reading “Five Little Peppers and How They Grew” and refused to play with her bored sister, who climbed a tree and fell. Decades later, when asked to choose “a book that mattered the most to you in your life” — that’s the group’s theme for the year — she selects “From Clare to Here.” That was the children’s book she read two weeks after her mother’s suicide, when “a woman drove up in a big black Cadillac and handed the book to Ava.”

This is the first of many red flags that will direct readers toward a conclusion just as predictable as the rest of the book group’s picks, which range from such warhorses as “To Kill a Mockingbird” and “The Catcher in the Rye,” to “One Hundred Years of Solitude” and “The Unbearable Lightness of Being.” Ava’s less-than-startling odyssey over the course of the year includes her rediscovery of the love of reading and great sex with a much younger book group member, which feels more like wish fulfillment than a plausible plot development (although he does have mommy issues).

It seems at first that a harrowing subplot involving Ava’s daughter Maggie will add some grit to this well-meaning but bland tale. She has dropped out of an art history program in Florence to follow a boy to Paris, and it’s immediately apparent that she’s a troubled young woman with a taste for drink and drugs. But Maggie, too, is eventually redeemed by books, thanks to a coincidence so glaringly implausible it’s likely to provoke groans of disbelief.

“I realized that we get to choose — darkness or light, life or death,” Maggie tells her mother. “I choose light. I chose life.” This touching declaration would be more effective if it weren’t echoed 20 pages later during a book group discussion, but belaboring the obvious is, alas, standard operating procedure in “The Book That Matters Most.”

Which is not to say that it isn’t agreeable. Hood writes smoothly, and there are flashes of wry humor to offset the generally anodyne tone. But the author of “The Knitting Circle” and “An Italian Wife” is capable of more complexity and depth, not to mention subtler plotting, than she offers here.

Wendy Smith is the author of “Real Life Drama: The Group Theatre and America, 1931-1940.

The Book That Matters Most

Ann Hood

W.W. Norton. 358 pp. 25.95