A lot of contemporary literary fiction does nothing for me. It doesn't attach to my brain. It's fine. It's not intense enough.

My favorite novelist, Virginia Woolf, once wrote in an essay that "moments of great intensity" are what matter most in life and in fiction. After a funeral, she wrote in a letter that she hated "the lack of intensity; the wailing & mumbling." In 1940, the year Germany bombed London, she wrote in her diary, "I live in intensity."

Intensity is also the novelist Garth Greenwell's subject. The word itself appears twice on the first page of his second novel, Cleanness, a subtly ironic title for the dirtiest novel the New Yorker has excerpted in ages. (None of the dirtiest passages appeared in the magazine.)

If you encountered those stories in the magazine and something felt slight about them, that's because they are not stand-alone stories; they need the context of the full book to have their full effect. One quality of this extraordinary novel is the way its intensities echo across chapters, flaring up in the life of one character and then another, crossing chasms of experience, illuminating new perspectives.

On page 29, the narrator (whose name we never learn) is saying to a man who is topping him—dominating him—"I want to be nothing, I want to be nothing." This top turns out to have a cruel streak, and as he becomes more sexually aroused, he becomes frighteningly violent, so much so that the narrator flees in a panic, uncomprehending, sobbing. One hundred pages later, the narrator is now topping someone, an unusual role for him, and as the bottom cries out, "I'm nothing, I'm nothing," the narrator notes darkly the feeling of violence surging inside him now, an "intensity or aggression... a kind of cruelty."

The narrator is an English teacher from the United States living in Bulgaria. The novel is full of beautiful writing about the pitfalls of teaching, the violence of politics, and the purpose of poetry, but the sex scenes are the most memorable. Few writers write about sex so well and with so much sensitivity.

Few writers write about sex so well and with so much sensitivity.

The brilliance and animal warmth of Greenwell's style, the depth of insight, and the range of empathy, confer on even gloomy subjects a kind of radiance. "Sex had never been joyful for me, or almost never, it had always been fraught with shame or anxiety or fear, all of which vanished at the sight of his smile, simply vanished, it poured a kind of cleanness over everything we did," the narrator says about yet another sexual partner, a man named R., the main love interest of the book.

After describing R.'s "offhand and accidental" good looks, "his disheveled hair and ruffled clothes, a beauty stripped of self-regard," Greenwell elegantly pries open R.'s inner life, revealing a torturous secret. During sex, R. makes "a small noise of desire or grief, I couldn't tell which." One of the book's many achievements is the way it dramatizes the paradoxes of men, the glowing anxieties they carry and conceal, and the way that roles (in sex, in society) have the power to trap or liberate them.

After reading one of the chapters about R., my boyfriend set down Cleanness and said, "Yeah, that one was intense."