What It Takes to Fully Participate in Life : CROSSING BROOKLYN FERRY by Jennie Fields; William Morrow; $23, 256 pages

Make no mistake: Jennie Fields’ second novel is an ode to Brooklyn’s gentrifying Park Slope district, a meditation on wealth and poverty, tradition and change, lust and guilt, and a call for women to take control of their lives--but at heart, it’s a romance.

Fields’ heroine, Zoe Finney, is a poor girl from Illinois who has married into money. Her husband, Jamie, is loving and gentle but prone to crippling depression. After the latest attack, he has remained in bed, wasting mutely away.

Zoe, who edits TV commercials for a Manhattan advertising agency, feels that she, Jamie and their 6-year-old daughter, Rose, will benefit from a move away from his oppressive family. So she trades their posh co-op apartment for an 1886-vintage brownstone in Park Slope, a close-knit Irish working-class neighborhood that is becoming a yuppie haven.

Next door to their 17-foot-wide, four-story manse live the O’Connors, who have inhabited their brownstone since World War I. The lower floors belong to philandering Jim O’Connor and his unhappy wife, Patty. For years, Patty has yearned after Jim’s younger brother, Keevan, who lives upstairs.

Keevan is everything that Jamie no longer can be. A high school English teacher, he’s virile, energetic and deeply engaged in the world.

Zoe fights her feelings, knowing that Jamie needs her more than ever, but her friendship with Keevan ripens into a passionate affair.

What to do? Fields (“Lily Beach”) neglects no device to put Zoe through the emotional wringer. She not only grew up over a shabby dry-cleaning shop; her parents were Holocaust survivors, incapable of love. Spurred by half-buried feelings of deprivation, she is a compulsive shoplifter.

Jamie’s family isn’t just rich; it’s a legendary political clan, like the Kennedys. He isn’t just depressed; his crushing malaise--dating to when, at 16, he drove drunk and killed people in a crash that was bannered in all the tabloids--resists therapy, shock treatment and the whole pharmacopeia of drugs.

There is much to like in “Crossing Brooklyn Ferry.” Fields is good at rendering the stop-and-start rhythm of relationships. Her writing is not only full-bloodedly sexual but vivid across a wide range of sensory experience: food, decor, clothes, weather. She puts her sympathies squarely on the side of people who have the guts to change, even if at first they seem silly--Patty’s liberation, no less profound than Zoe’s, begins with peroxided hair and a push-up bra.

The novel’s fairy-tale aspects are grounded by Fields’ chronicle of a whole year in the life of Park Slope. Now and then she echoes the theme of the Walt Whitman poem from which her title comes: that human constants underlie change. A dying man, a neighbor of Zoe’s, “feels young, and he is bewildered that the man in the bed is him.”

Such moments are genuinely moving. In contrast, there is something unsettling about the way Jamie is viewed, even by his daughter and sister, as “living dead,” as “self-absorbed,” as a drain on the resources of those healthier than he. His depression isn’t his fault, but it might as well be; his task, when he awakes from his stupor and discovers his wife slipping away--a task Fields tries to present to us as heroic--is to realize that he isn’t qualified to participate fully in life and that he should get out of the path of those who can.