The Flattery sisters, to quote the song, are doing it for themselves.

Irish novelist Caoilinn Hughes' "The Alternatives" centers on four siblings, all in their 30s, each accomplished and independent. None is married, though Rhona has a young child, and Maeve is considering hitting up her Croatian mime housemate for a sperm donation.

Despite some head-scratching narrative slowdowns, "The Alternatives" rarely fails to impress and, frequently, even to wow. It's a novel of tiny, telling details alongside big ideas. Here's a minor character in a brief appearance at a village pub, her asymmetrical arrangement of dimples giving her "an unbroken expression of cordial acceptance." Here's a section about threats to the democratic process. Here's Nell, quoting an entire poem by Emily Dickinson.

Hughes is uninhibited, intensely perceptive. Her oddball similes sometimes click like magic, but occasionally go clunk. In spiky prose, she fearlessly explores the worlds of geology teacher Olwen, philosophy professor Nell, celebrity chef Maeve and political scientist Rhona. She deftly cuts from detailed scenes of undergrads learning about tectonic convergence to a lecture on Aristotle, from a high-end catered dinner to an all-night dance fueled by Ecstasy.

After introducing her cast in a series of potent, captivating opening chapters, Hughes sets into motion a fairly straightforward plot. Olwen suddenly leaves her partner and his two young sons, as well as her teaching position, riding off at midnight on a bicycle into the Irish countryside. Alarmed by her disappearance, her sisters launch a search-and-rescue mission.

When they all end up at a rundown house that Olwen has taken over in the middle of rainy nowhere, the novel becomes a screenplay that employs italic stage directions for much more than scene-setting, exits and entrances.

Here Hughes' sure grip on her material loosens, becoming digressive and idiosyncratic. A subplot about political repression in Chile fizzles. The sisters' reunion is marked by indirection and hostility, with everyone seeming afraid to ask Olwen the obvious questions: Why'd you flee? Where is your new life headed? It's as if such direct queries and Olwen's potential response have become beside the point, that her belief in "peer-reviewed fact" places her at odds with the vagaries of barely explicable human grief. Mental illness is not really evidence-based.

Chinks in the sisters' armor of high achievement surface. Olwen drinks too much. Maeve's cookbook empire faces a setback. Nell has an undiagnosed, disabling medical condition. The closeness of the women, forged as teens after their parents died suddenly, shows signs of crumbling under the weight of old hurts and contemporary pressures. A wicked sense of humor lurks among all this darkness.

Career challenges meet those created by ticking biological clocks and relationship mishaps. Faults are found. Alliances form and dissolve. Through Olwen's earth sciences background and deep eco-pessimism, we learn about imminent threats to the landmass of Ireland itself. "The drumlins we'll leave behind will be made of Lego astronauts and Kalashnikovs and radioactive chicken bones and Jesus-in-a-manger figurines," she warns her students on a geology field trip.

"The Alternatives" contains multitudes. Its mysteries and complexities reward a second reading. Its weaknesses render it human. The book's ending is a stunner. And Olwen, Maeve, Nell and Rhona make it unforgettable.

Claude Peck is a former columnist and editor at the Star Tribune.

The Alternatives

By: Caoilinn Hughes.

Publisher: Riverhead, $28, 338 pages.