Two old buddies meet up in a Dublin pub. They have a couple pints. And a couple more. They rarely get together anymore, and this is supposed to be fun. Instead, they spend most of the night talking past each other. There are some veiled insults. One monopolizes the conversation. The other wishes he hadn’t left home.

Narrowly focused but deceptively complex, Roddy Doyle’s new novel is called “Love.” At first, given the obvious resentment between his co-leads, the title feels inapt. In time, though, when it becomes clear that the Irish author has much more on his mind than a single strained friendship, it’s a perfect fit.

Davy, our narrator, has lived in England for years, but his father’s failing health has brought him back to his native Ireland. One night, he meets for beers with boyhood pal Joe, a decision Davy regrets almost immediately.

Joe has big news: He’s left his wife and moved in with a woman he and Davy hung out with once or twice when they were in their 20s. Now nearing 60, Joe babbles like an impulsive schoolboy, unwilling to stop talking about his new crush but unable to express why he finds her so captivating. It’s annoying, sordid. Things get tense. Joe says something dismissive about Davy’s wife, Faye. Davy feels the urge to flee, but loyalty roots him to his bar stool: “There was something — a feeling, something behind my eyes. This might be the last time I’d spend with Joe. We both knew it.”

This is a thin story on which to base a novel. But Doyle, the author of tales that feature crackling wit and dialogue — “Paddy Clarke Ha Ha Ha” earned him the Booker Prize — knows what he’s doing. For him, the frustrations of the Davy-Joe friendship are a prism through which to view Davy’s other relationships, those that truly sustain him.

Pretending to hang on Joe’s words, Davy spends much of the night in a kind of reverie. He recalls how he and his father shared silent meals after Davy’s mother died when he was 12: “The radiators went cold. … I watched television till the programmes stopped.” He feels grateful for having met confident, articulate Faye, whose vigilance kept him afloat during a recent health scare: “She wanted to feel my eyes. She wanted to lift me out of death.” He chuckles to himself when remembering the look on his hip teenage daughter’s face when he suggested he’d accompany her to an indie rock concert.

These tender, relatable scenes take up fewer pages than Davy’s ramblings, but they form the heart of the book. They also raise a timeless question: What do faltering relationships tell us about those that endure? A lot more than we might realize, according to this subtle, observant novel.

Kevin Canfield is a writer in New York City.

Love
By: Roddy Doyle.
Publisher: Viking, 336 pages, $27.