Nick Laird’s new book, “Glover’s Mistake” ($25.95), is enticing. You want to know what it was, don’t you? Perhaps, like Glover, you too make mistakes. Perhaps you feel unjustly punished, worthless in the eyes of the world.

You like this Glover already, before you’ve even opened the book — precisely because he has made a mistake. And you don’t even know what it was. You open the novel ready to forgive, proving your largess. That is what humans do; they forgive. What a great person you are.

Laird, bless his heart, knows exactly how hard people try to do the right thing. He knows how people sour, like (yes) spoiled milk. He knows how love is supposed to fix everything and how it almost never does. These are important things to know for a writer whose novel is based on characters, not plot.

“Glover’s Mistake” is a triangle novel (specifically an equilateral triangle). There’s Ruth at the top, 45, a very successful artist, thrice-divorced with one very bitter daughter and a trail of lesbian relationships.

There’s David, 35, an English professor with a secret life — a blog he calls the Damp Review. And there’s James Glover, 23, a handsome bartender who doesn’t know much about art but is a swell guy. James and David are roommates.

Ruth was once David’s professor in college. James is cool. David is bitter and rancorous. In his blog he writes caustic, ironic reviews of movies, ar and books and, outside of his blog, he doesn’t have much of an actual life. Who do you think Ruth is going to fall in love with, especially after a nasty divorce?

Well, David is surprised (perhaps because he spends so much time at his computer and not with real people). In a half-hearted way, he had a thing for Ruth. To his credit, he tries to stomach it. James and Ruth become lovers and get engaged. David tags along for a bit and then tries to sabotage the relationship.

That there is not too much plot is fine because Laird is so deft with character — the many ways we turn more and more inward and devour ourselves like creepy Cubist robots.

The novel slinks forward by snipes and barbed comments; the triangle spins and wobbles off kilter. The love triangle is certainly not a new thing in literature; the tension and pressure build until the shape cannot hold.

What is new is the cultural context with which Laird fills the rest of his canvas. David and James are iconic, polar opposites in today’s world: the guy who believes that you “make your own luck” vs. the guy who believes that “everything happens for a reason.”

Some of the most beautiful writing (no irony, no rancor, no sarcasm) in “Glover’s Mistake” is in Laird’s descriptions of London. These passages are so gorgeously specific and evocative, you’d almost think the guy was homesick, living elsewhere.