Sometimes a literary character's hold on its author (and readers!) is too strong to ignore. While many sequels feel like attempts to milk a cash cow, others, like Elizabeth Strout's Olive Kitteridge novels, bring fresh delight.

Long Island, Colm Tóibín's heartrending follow-up to his beloved 2009 novel, Brooklyn, is the rare instance in which a sequel is every bit as good as the original.

Brooklyn, which was further popularized by the eponymous 2015 movie starring Saoirse Ronan, concerns a young Irish immigrant torn between her new home and her old one in the 1950s. Eilis Lacey, recently sent to America by her family for better prospects, returns to Enniscorthy in County Wexford, her hometown and Tóibín's, for the funeral of her beloved older sister. Her mother, alone now that Rose is dead, doesn't want Eilis to leave. But Eilis can't bring herself to tell her — or anyone, including the man with whom she strikes up a romance — that she's married to an Italian-American plumber she met at a dance in Brooklyn.

Long Island picks up Eilis' story 25 years later, when she learns that her husband, Tony Fiorello, has impregnated one of his married clients, whose husband has categorically rejected the child. Eilis, too, adamantly refuses to have anything to do with the baby. Tony's family, who live cheek-by-jowl in a cluster of houses in Lindenhurst, Long Island, have always viewed Eilis as an outsider. To escape the tremendous pressure from them to accept this child, Eilis decides to absent herself when the baby is due by returning to Ireland for the first time in more than 20 years. She arranges for her two teenage children, Rosella and Larry, to join her in time for the 80th birthday of the grandmother they've never met.

Everyone in Enniscorthy finds Eilis profoundly changed, "like a different person." She tells no one why she's there, including her testy mother, who lets Eilis know how insulting she finds her daughter's patronizing attempts to fix up her home after such a long absence.

When Eilis stops in to see her former best friend, Nancy Sheridan, widowed for five years, neither woman is open about what's going on in their lives. Nancy, not wanting to overshadow her daughter's upcoming wedding, is keeping her impending engagement to Jim Sheridan, the pub owner whom Eilis jilted 25 years ago without an explanation, under wraps for the time being.

Ah, secrets. Tóibín, whose flawless ear captures the constant murmur of gossip that courses through small towns like Enniscorthy, is also sharply attuned to the unspoken. Such circumspection has long underpinned his fiction, including The Master and The Magician, in which he depicted the complicated lives and carefully repressed sexuality of literary titans Henry James and Thomas Mann with graceful nuance.

As always, Tóibín's narrative restraint heightens tension and allows readers to fill in the blanks. We marvel at his skill as we watch his characters in Long Island become ensnared in the elaborate web of strategically withheld information and calculated partial truths he has them spin.

Long Island shares with The Magician and story collections such as The Empty Family a concern with the pain of the exile's return after a long absence. But while in Brooklyn, Eilis' relationships with two very different men separated by thousands of miles underscores the theme of an immigrant uneasily straddling two cultures, Long Island finds her more deeply rooted in America. Anchored by her American children and her bookkeeping job, Eilis' future wouldn't be in question if not for the situation with Tony's baby. Her subsequent return to Ireland causes a pull not between countries but between reason and romance, moral obligations and what the heart desires. Among the many discussion-worthy questions this novel poses: Which is worse, to betray someone, or to betray your feelings?

Tóibín's portrait of Eilis is sympathetic, both in her youthful dissembling and in her current decisiveness, which borders on intransigence. Long Island finds her not just more mature but more self-assured after decades of marriage, motherhood, and holding her own against her intrusive in-laws. Her imperatives — what she feels she has to do, whether about the unwanted baby or her future — are non-negotiable. When Jim talks about his sadness over her abrupt, hurtful parting years ago, Eilis responds without apparent remorse or sympathy: "It was the way it had to be." But the changes she is contemplating this time involve many people and "many uncertainties," which require time to navigate.

Tóibín handles these uncertainties and moral conundrums with exquisite delicacy, zigzagging back and forth through time to build to a devastating climax. The tragedy of this novel about the universality of longing is that, even 25 years on, Eilis, however decisive, is still not in control of her own life.