Lorrie Moore, whose short-story collections (Who Will Run the Frog Hospital? and Birds of America: Stories) are known for wit that sparkles and bites, has earned book-of-the-year status for her recent novel A Gate at the Stairs. Here again she excels with prose that projects barbs of humor from the point of view of heroine Tassie Keltjin. Tassie skewers both the provincial town that she’s from (the local restaurant features “cheese curd meatloaf and steak ‘cooked to your likeness’”) and the liberal city where she is attending college. (The author teaches English at the University of Wisconsin in Madison.)

For most of the book, the plot is Tassie—her day-to-day and semester-to-semester life as a 20-year-old coed who’s escaped an unhappy mother and the confinement of Midwestern provincial life for the freedom and excitement of the university experience. She bonds with Murph from Dubuque, who calls the city “Du-ba-cue” and matches Tassie’s undergraduate sassiness with flip, outrageous opinions of her own. The friendship helps Tassie ease past her insecurities about home, sex and her newfound independence and is one of the brighter spots in the novel.

Tassie loves to read and immerses herself happily in the writings of Sylvia Plath, Simone de Beauvoir and Chaucer. Despite her insecurities about herself and her loneliness when Murph disappears to live with a boyfriend, Tassie is happy: “Someone had turned on the lights.”

She finds a baby-sitting job with Sarah Brink, owner of an upscale restaurant who, with her husband, Edward, is in the process of adopting Emmie, a mixed-race baby. Sarah and Edward, who are white, see raising Emmie as a holy mission in a racist environment. On Wednesday evenings, they invite other liberal adoptive parents to their home, where they debate the manifestations of racism in the culture and the challenges they face as advocates for their children. Their exaggerated political outrage, fueled by wine, goes on for pages. Moore seems to be venting, and the novel stalls. She makes the accusation of racism more effectively with action, especially in a scene in which a carful of teens shout out a racial slur, and when women in the grocery store stare at the white mother (or baby-sitter) with a black child.

Tassie quickly grows to love Emmie, but she remains instinctively wary of Sarah and Edward and sees that their oppressive focus on political correctness and an upscale style of parenting often omit common sense. However eager Tassie was to escape the prov inces, she left home with a keen intuition of right and wrong: she is alert to what’s false in a person, exhibits a strong sense of justice and injustice, and appreciates the responsibilities of raising and loving a child. For Sarah, in contrast, life seems oppressive. As she runs from restaurant to home she sighs to Tassie, “In everything I do there seems to be some part missing. I’m discovering that it is almost impossible to be a mother and also to do anything of value outside the house.” Meanwhile Edward seems more interested in the baby-sitter than in the baby.

Tassie prefers being alone with Emmie, taking spring walks with the baby in her “kick-ass American stroller.” She contrasts her love for the baby with her emotional distance from her mom. “It was a beautiful thing, having a little girl in tow. Why hadn’t my own mother known? Perhaps there was too much winter permanently in our veins.”

Winter break at Tassie’s farm home that year is bleak, from its unseasonable thunderstorms to the family’s lackluster efforts at celebrating the holidays. There is little celebration—either of Hanukkah (from her mother) or of Christmas (from her father). “Perhaps,” she says, “my mother had lost interest in this ostensibly Christian custom now that we had grown, and my father didn’t really know how to take over.”

This bright, funny coming-of-age novel might have been stronger with fewer pages; it may be that Moore’s talent is better showcased in the smaller dose of a short story. After a few hundred pages, I expected more substance, some resolution of Tassie’s crises, some new realization as she sifts through her life experiences.

But a more serious problem is the shift from the vitality of the first half to the storm that gathers and breaks out in the second half. Unexpected fates begin to descend when Tassie’s splendorous relationship with her first love takes a dive. Granted, relationship endings are de rigueur in coming-of-age novels; but this breakup comes with a bizarre, even ominous secret—one that sets off a wrenching revelation followed by another mishap. The disasters rip through the book, pelting Tassie and the reader too. Enough already.

I felt bereft along with Tassie and wondered what message Moore is hoping to convey in the novel. Is she hammering home an awareness of life’s tenuousness? Is she warning us that the world is callous and that no one, including the God “from the provinces,” will show up to redeem us from misery? Is she pointing to the carelessness of many of her characters? I couldn’t decide.

There’s a limit to how much sadness a reader can call entertainment if an author hasn’t come along to keep the reader company. My sense is that Moore herself does not know what to do with the contrast between her own keen and funny insights and the reality of foolishness, error and despair that she sees in human beings. In A Gate at the Stairs, the combination is like fingernails on a blackboard.