In his 1995 book, The Sign of the Cross: Travels in Catholic Europe, the Irish journalist and novelist Colm Toibin claimed to discern a new optimism afoot in his native land. In recent decades, he wrote, the traditionally dour outlook of a populace “desperate to hold on to the small improvements in their lot” had given way to the confidence of “a new generation wandering around on a Saturday night with no innate fear.” For the first time, being young in Ireland meant growing up in a “climate of hope.”

Testing this thesis is the business of Toibin’s fourth novel, The Blackwater Lightship, which was a finalist for last year’s Booker Prize. Set in Dublin and rural County Wexford, the novel summons three generations of an Irish family and lets them have at one another - a clash of country versus city, conservative versus liberal, old ways versus new. At the center of the family skirmish stands Helen O’Doherty, a 31-year-old school principal living in Dublin with her teacher husband, Hugh, and their two little boys. Helen and Hugh are the enlightened young Irish: she consults books on parenting; he cooks; and when their 6-year-old catches them at lovemaking, they’re able to joke about it. They have built an addition to their house, “a large, square, bright room which served as kitchen and dining room and playroom.” The room resembles their life - spacious and cheery, comfortably handling a blurring of roles.

And yet there are shadows. Amid the “sweet energy” of her family, Helen feels a lurking ambivalence. She’s troubled by obscure premonitions of failure in her marriage and by “raw areas in her which were unsettled and untrusting.” As her husband sings a rapturous Irish ballad at a party, she feels an “urge to resist him, keep him at bay.” Something is amiss, we sense, as we watch her wary withholding; there’s some hurt in her past she won’t face.

She’s forced to do just that, however, by the news that her brother, Declan, is desperately ill in a Dublin hospital. In fact, he’s dying of AIDS. Declan’s wish is to be moved to the home of their acerbic grandmother, Dora, who lives on a cliff overlooking the sea. Guilt-stricken to discover that her brother has been ill for years and never confided in her, Helen moves in as well (husband and sons having been packed off to the in-laws in Donegal), along with her mother, Lily, and Declan’s friends, Larry and Paul.

As a long week in the old house unfolds, Declan’s health deteriorates, and his anguished mortality exerts a pressure of intimacy and confession on the others. Helen gives vent to an “awful bitterness” at her mother, dating back 20 years to her father’s death from cancer, when Lily sent her and Declan off to Dora without ever telling them their father was dying. “I’ve never trusted you again,” Helen tells her mother now. “I did what I could for you,” Lily fires back, “and you never gave me an inch.” All truths must out as old griefs and grievances are revisited in a group encounter session conducted under the deadline of an impending death.

In a previous novel, The Story of the Night, Toibin brought a group of gay men to another seaside house - in Argentina - to face the ravages of illness. Admitting women into the circle lets him reconfigure traditional notions of gender and role in a kind of ad hoc family. Larry and Paul serve as Declan’s chief comforters; they’re the true mothers, with Helen and Lily (both ambitious career women) taking lessons. And not only in nursing. The men tell their coming-out stories with a hard-won honesty that is both example and prod - the gay man as midwife to these women’s reluctant emotions. For Dora, meanwhile, it’s all too much, this openness, and when Larry confesses that as a younger man he slept with all four sons of a family in his old neighborhood, she bursts out in dismay: “Oh guard your heart, that’s my advice to you, guard your heart and be careful of yourself.”

The most engaging moments in The Blackwater Lightship follow the interplay between gruff, ornery Dora and the three men, who succeed in clasping hands across a gulf of age and sensibility. (”You should meet my granny,” Declan tells Paul at the outset. “She’s a real paint remover.”) In the background, Toibin builds an atmosphere of abiding rural gloom: a crumbling cliff and stony stretch of beach; the ruins of a neighboring house; Dora’s own house, musty and dank, its rooms swept at night by the beam of a nearby lighthouse.

His human interiors prove less convincing. Too often, Helen’s passages read less like renderings of an inner state than notes on one: “She realized that the bitter resentment against her mother which had clouded her life had not faded.” “As she saw him in the kitchen, she felt an intense hostility to him, which she knew she would have to keep under control.” There’s a feel of points too clearly made, almost as in young adult fiction, where no doubt is left about the main character’s resolve. Here is Helen lying awake in bed, worrying about her sons after a harrowing night with Declan:

”She resolved to think harder and pay more attention so that Cathal and Manus could feel secure in the world and feel none of the currents which went through her grandmother’s house now every moment of the day. As she turned and tried to sleep, however, she knew that anyone who was close to her must have learned long ago to live with and manage this web of unresolved connections. She clenched her fists and swore that she would do her best to protect them.”

Toibin has a stubborn penchant for melodrama. “As she stood there, the sky darkened.” “The room was darkened but Helen could make out Declan in the bed.” “The colors were darkening now, night was coming down.” “A dark shadow seemed to pass in front of the car.” “As darkness fell, Helen drove her mother into Wexford.” “The dark thoughts about the old house continued to trouble her.” “She could not step out from her mother’s dark shadow.” And on and on. This is an author who elsewhere has lamented literature’s habit of presenting gay life as “darkly sensational,” and yet he himself dims the lights at almost every turn.

Meanwhile, his straight characters seem never to have entertained a single thought about homosexuality. Watching Paul strip to swim, Helen marvels to think that “if he saw her undressing ... it would mean nothing to him.” This naïveté, and the way it elicits the men’s coming-out stories, makes the book read at times like a primer for citizens of good will eager to welcome the gay people they’ve only now realized are living among them.

Yet it’s reductive to view “The Blackwater Lightship” as a gay novel. Helen’s tabula rasa-like curiosity about her brother’s sexuality - how strange and new this was for her” - forms part of a broader innocence. Indeed, to an American reader, the novel seems keyed to some earlier historical and cultural moment: an era when having central heating still impressed, the loss of faith remained a burning literary subject, the very idea of personal fulfillment conflicted fiercely with the obligation to parents, and nobody talked about sex - or anything else. Helen’s encounter with a psychiatrist (”a man in his 50’s with a beard who was always in his stockinged feet”) seems lifted from a World War II-era New Yorker cartoon; while Declan, describing his mother, uses “a new word ... picked up from Paul”: needy.

While we needy Americans by now take for granted the therapeutic bent of contemporary life, “The Blackwater Lightship” resurrects an innocence, and a corresponding excitement, about the liberating promise of bringing secrets to light, whether they’re about your sexuality or your old, buried anger at Mom. As Toibin’s characters confess their way toward redemption, we sense that it’s really all about talk. “I became interested in my own happiness,” Helen says, by way of explaining her long estrangement from her mother and grandmother. In the world of this novel, happiness means rejecting the old hierarchies of church and family, with their oppressive demands and stifling repressions, to seek instead the family of those who will share your pain, who will help you get it all out. In Toibin’s new Ireland, home is where the healing is.