Motherhood, we're told, is a miracle, a blessing, a gift. That's the unmistakable message that the mass media have hammered home for decades — women who give birth are expected to be grateful, uncomplaining, never expressing any negative emotion.

But for Claire, the narrator of Claire Vaye Watkins' stunning new novel, "I Love You But I've Chosen Darkness," the situation is much more complicated. "Motherhood had cracked me in half," she reflects. "My self as a mother and my self as not were two different people, distinct."

Claire is a professor and author living in Michigan, who's found herself suffering from severe postpartum depression after the birth of her daughter. Her open marriage is faltering, and she's alarmed when she finds teeth growing inside her vagina. Her doctors think she's "drug-seeking and insane," and she finds her life as "an overweight and deeply ambivalent mother [and] a wunderkind burnout rethinking her impressive career" to be intolerable.

Claire takes a flight to Reno, Nev., for a speaking engagement, while her husband stays with their daughter. She's looking forward to the visit — kind of. While she still has friends in the city where she used to live, she knows she'll be forced to confront her childhood, spent in California and Nevada. Her upbringing wasn't a happy one — she grew up the daughter of a former Manson family member (as did Watkins herself) and an opioid addict, both of whom died too young.

When it comes time for her to return home, she doesn't. She bounces around from town to town, staying with friends, strangers and a lover who she's developed serious feelings for, a violation of her agreement with her husband: "We could have sex with other people or fall in love with other people, but not both. Not both in the same person. This was the rule I broke."

Claire breaks several rules in this novel, and she doesn't quite regret any of them. "The truth is I cannot play nice and don't want to, but want to want to, some days," she says. And Watkins refuses to judge her harshly for this; the character is that rarest of things — a woman whose questionable decisions remain unpunished. That's part of what makes this novel so refreshing: At no point does it descend into a morality tale.

Readers who know Watkins from her first two books are bound to be surprised by this novel. It's messy, out of pocket and unapologetically transgressive. By naming the protagonist of the book after herself and giving her similar biographical details, Watkins seems to feel freer, more willing to take risks.

And it pays off. "I Love You But I've Chosen Darkness" is a wild, hilarious novel, told with a contagious, unchained ferocity. It's a wonderful book by an author who's quickly proven herself indispensable to American literature.

Michael Schaub is a member of the board of the National Book Critics Circle. He lives in Texas.

I Love You But I've Chosen Darkness

By: Claire Vaye Watkins.

Publisher: Riverhead, 290 pages, $27.