Delia Ephron’s novel “Siracusa” takes a skeptical look at that most perplexing of institutions: marriage.

The author Delia Ephron (Elena Seibert)

Some readers will recall that in 1983 Ephron’s late, much lamented sister Nora published “Heartburn,” the definitive novel of a Washington marriage gone wrong. “Siracusa” takes a more expansive look at matrimony and its discontents. Whereas Nora Ephron’s “Heartburn” was famously inspired by one errant husband, her sister examines two marriages and has one of the husbands proudly declare: “In Italy men cheat. Everywhere men cheat.” In this novel, at least, that’s the gospel truth.

The story centers on two couples vacationing together in Italy. The four of them take turns telling the story, and their views of events rarely coincide. One couple is playwright Michael and magazine writer Lizzie, who live in Manhattan. The other consists of Finn, who owns a restaurant in Portland, Maine, and wife Taylor, who works for the city government there. They are accompanied by their 10-year-old daughter, Snow, so named because she was born during a blizzard.

The couples are not close friends, but Lizzie and Finn had a brief affair 14 years earlier, when she was 29, and have kept in touch; this led to the ill-fated vacation that unfolds before us. We learn at the outset that both men, Michael and Finn, are having affairs with women back home. Michael, who has a large ego and a novel he’s struggling to finish, is bored with Lizzie. Lizzie, bright, good-hearted and sexy, is trying to keep their marriage afloat. In Italy, her ex-lover Finn pursues her, but she insists on being faithful to Michael. Neither man likes the other, and the same is true of the two women.

It is Finn, miserable in his marriage and yearning for Lizzie, who utters the book’s defining question: “How the hell did we end up in love with the wrong people?”

Finn’s wife, Taylor, is a spectacularly self-centered creature who recalls certain characters in Jane Austen — in “Pride and Prejudice,” for example, the sanctimonious clergyman Collins or the deplorable Lady de Bourgh — who are so astonishingly awful that one can only gaze upon them in horror. Taylor and Finn married out of sexual attraction that has long since departed; they remain together only because of love for their daughter.

Snow is beautiful and said to be very bright, although she rarely speaks, because her mother endlessly smothers her with praise, advice and criticism. One quotation will suggest the problem: “Because of her beauty and innocence, I discussed perverts with her when she was five years old.” This enigmatic child becomes central to Ephron’s story.

"Siracusa" by Delia Ephron (Blue Rider )

The five of them meet in Rome, then proceed to the ancient city of Siracusa in Sicily. Taylor hates the place — it offers no five-star hotel — but the others eat, drink, flirt and argue harmlessly enough until unforeseeable events lead to ever-increasing suspense, conflict and heartbreak.

A few more quotations may suggest the spirit of things:

Lizzie on her long-ago affair with Finn: “What was I doing with him? What? He was a Republican. Every digging deeper led to massive disagreement, even screaming, but I was having fun. . . . Finn was dessert. To take him seriously was to commit to an all-sugar diet.”

Lizzie on Michael’s appeal: “His physicality made him more compelling than the other male journalists and writers we hung out with whose only weapons were wit and sarcasm.”

Finn, blissed out: “Got to say, the Piazza Duomo was the most beautiful place I’ve ever been stoned. I pondered it while I sat dumb and happy in one of the sprawling cafes. Harmony. Everything in harmony. Sunlight sparkled off pink marble. Was it pink or is that the grass talking?”

Lizzie on marriage: “There are some people who shouldn’t marry. Some people are best single, and pity the ones who marry them.”

For much of the way, “Siracusa” is a sophisticated, elegantly written, delightfully cynical look at four middle-aged Americans, not unlike people most of us know, as they struggle to make sense of their lives. Then, abruptly, the story darkens. All readers may not share my admiration for its shocking conclusion, but it’s that sudden glimpse of tragedy, even of evil, that gives Ephron’s novel the feel of a classic.

Patrick Anderson reviews mysteries and thrillers for Book World.

Siracusa

By Delia Ephron

Blue Rider Press. 288 pp. $26