Is bad behavior in marriage back? In fictional marriage, I mean. For years, heterosexual matrimony in American novels has seemed rather like it’s become a trap for the female protagonist: Unhappy or misunderstood by her spouse, she may act out or seek retribution; whatever her behavior, though, readers are meant to see that it’s attributable to her environment—in other words, that she’s not really in the wrong. For this plotline to work, the wife must be attuned, sometimes newly so, to herself, her unhappiness, her desires—a fictional extension of the powerful, if reductive, idea that women can protect themselves from harm by understanding their own wants and limits.

In daily life, of course, human desires and boundaries are changeable. The feminist philosopher Katherine Angel writes, “Self-knowledge is not a reliable feature of female sexuality, nor of sexuality in general; in fact, it is not a reliable feature of being a person. Insisting otherwise is fatal.” Self-awareness has certainly killed sex (and sexiness) in a lot of novels; it’s killed a lot of novels, in fact. A story without badness isn’t much of a story, and a story whose hero has perfect self-knowledge is a story utterly devoid of suspense.

Stories about marriage are no exception to this rule. There’s an unbearable flatness to any book whose protagonist is always justified in her actions—or, for that matter, always able to justify them to herself. After years of reading such dead tales, I found both delight and hope in the critic and memoirist Lauren Elkin’s debut novel, Scaffolding, a tale of two slippery adulterers who consider understanding oneself an impossible—or, at best, incompletely possible—task. Its protagonists, Anna and Florence, are psychoanalysts who live in the same Parisian apartment nearly five decades apart, in the 2010s and 1970s, respectively. Both women have crises of faith in language, in intellectualism, in their role as a therapist and as a wife. Neither wants to leave their marriage, but both launch intense, clandestine affairs.

Anna and Florence don’t totally understand their motivations for cheating. They act on impulse—in Anna’s case, for what seems like the first time in her life—and yet each seems to recognize that her affair is a voyage of discovery. Elkin writes these events as complicated adventures in wrong decisions—which, crucially, she neither justifies nor condemns. She lets her characters be bad yet ordinary, bad yet sympathy-inducing, bad yet worthy of a good life. In a sense, their badness improves their situation. Their lack of self-awareness, their tendency or ability to submit to their id, gets them closer to what they consciously want: some privacy within their marriage. Just as Scaffolding argues that we can’t know ourselves fully, it makes plain that we can never completely know one another—and that there’s nothing fundamentally wrong with that, even when it leads to bad behavior; even when it breaks our hearts.

Scaffolding is about feminism as much as it is about marriage. Florence, its ’70s protagonist, is a psychoanalysis student who spends her free time with consciousness-raising groups. She commits herself to flouting convention, even though her marriage is fairly traditional: She cooks and cleans, and is busy redecorating the apartment that she and her husband, Henry, inherited from her grandmother, who survived the Holocaust. Elkin swiftly makes apparent to readers that Florence’s feminist rebellion is also a rejection of the (largely Christian) “Franco-Français” society that deported her family—something Florence herself seems not to notice. She’s too busy thinking about the affair she’s having with one of her professors. Anna, in the 21st century, is less rebellious and much less happy. She’s suffering from depression after a miscarriage, spending hours immobile in bed, “as if a large sheet of cling film were pinning me in place.” Sexually, she’s shut down; her husband, David, is working in London, and she declines to go with him and struggles to engage in any intimacy when he visits her in Paris. Her only live connection—very live, it turns out—is with Clémentine, a feminist artist in her 20s who grows determined, and successfully so, to draw Anna out of herself and into the world.

[Read: How should feminists have sex now?]

But even as Anna begins recovering from her depression, its effect on her career is devastating. Formerly devoted to her analysis practice, she’s now stopped valuing her profession. “Why look in other people’s narratives for the metaphors, the gaps, the gaffes, the subtexts, that point you to what they themselves may or may not realise?” she asks herself. “Maybe the words merely point to themselves.” Readers see her apply this feeling to her own life, expending less and less effort on making sense of her behavior. Florence follows a similar trajectory, though as a result not of trauma but of going to Jacques Lacan’s lectures and having an affair with a Lacanian psychology professor. (Don’t worry: Although Lacan famously deconstructed language, which led, in his case, to highly abstruse writing, Scaffolding does not. Elkin’s prose is elegant and straightforward, with just enough experimentation to suit its ideas.) “We have to absorb what we’re learning without passing it through language,” she tells a friend—no easy job for a shrink. But both Florence and Anna learn to see conscious thought as a scaffold, with impulse and desire as the real, substantial building it encases and supports.

Florence tries and fails to explain the intensity of her feelings for the professor she’s having an affair with; she tells herself he’s a stand-in for something but has no idea what. At the same time, she’s mystified by the fact that the affair is a “big, big deal” to her when she’s out and about in the daytime, but the moment she returns to her “evening life” with Henry (a cheater himself, not incidentally), thoughts of her lover either vanish or fuel the sex life that is the core of her marriage. Secrecy and deception as aphrodisiac—this may not be moral, and yet, Florence decides, it’s “exactly how [marriage] should work, and exactly not how it is supposed to work.”

Anna, for her part, keeps more secrets from herself than from David. She nurtures an attraction to her neighbor Clémentine without permitting herself to notice, though the reader can’t miss it: Anna, otherwise cut off from her body, is so physically attuned to her friend’s presence that she describes her as “her own charged atmosphere.” It’s through Clémentine, in fact, that Anna reencounters an ex whom she desires so intensely, she sleeps with him almost instantly, even though doing so means betraying both David and Clémentine. Unlike Florence, Anna doesn’t attempt to explain her feelings or actions to herself. She knows her behavior is wrong, yet she also knows how alone she’s been, how solitary and isolated from her husband her depression has made her. Having an affair punctures her cling film. It might be bad, but it also returns her to her marriage and her life.

Scaffolding isn’t really suggesting that adultery and secrecy are good for a marriage. Rather, the novel treats these things as bad but normal and manageable—and preferable to a total loss of connection. When Clémentine cheats on her boyfriend, she tells Anna the cheating is a disruption that can be “absorbed back into the relationship.” Novels that leave wrongdoing out of their worlds imply that no transgression, marital or otherwise, could be that small, and that for a character to do something genuinely harmful would bring their whole life crashing down. Our broader cultural impulse toward hyperconsciousness is rooted in the same idea. It reflects an inability or unwillingness to tell the difference between big bad things and the small bad ones—and, by extension, to forgive the latter.

[Read: A grim view of marriage—and an exhortation to leave it]

Elkin puts some big badness in Scaffolding to draw out this distinction. Clémentine is part of a brigade of women who graffiti anti–domestic abuse messages on Paris’s walls. Their work presents a vision of feminism very different from the one in Florence’s consciousness-raising groups, which are all about knowing oneself: For Clémentine, protest is the only way women can resist misogyny. Anna’s first positive emotion in the novel is a response to the graffiti: “Aren’t they incredible?” she says, pointing one out to David on one of his visits from London. Florence, meanwhile, isn’t just involved in raising her own consciousness. She also keenly follows the Bobigny trial, France’s equivalent of Roe v. Wade. Both characters are highly aware of how dangerous life can be for women. Compared with unsafe clandestine abortions or spousal violence, some cheating means nothing; but compared with the flatness of Anna’s day-to-day life and the conventionality of Florence’s marriage, their affairs have immensely high stakes.

Scaffolding strikes this balance well. Elkin is deft but clear in reminding readers that there’s a distinction between badness and evil, or badness and hate. She writes Florence’s and Anna’s marriages as immensely loving ones, despite their holes and wobbles; in such relationships, the novel seems to argue, it is conceivable—though not guaranteed—that almost anything can be forgiven or absorbed.

Neither Florence nor Anna knows why they cheat on their husband. Perhaps more important, neither of them knows why they love their husband. In a novel less invested in psychological mystery, this would signal crisis for the fictional marriage. In life, it’s the most normal thing there is. Complete self-awareness is both an unattainable standard and a false promise, as is complete transparency with someone else, no matter what your wedding vows say or suggest. Accepting this fact is terrifying. It turns commitment into suspense. In reality, many of us prefer not to acknowledge that, which is more than reasonable: Who goes into their marriage wanting deception and drama?

Novels, though, are built to let us test-drive uncertainty—to feel it without living it. Where marriage is concerned, this is an important option for many of us to have. Marriage stories whose protagonists never slip up don’t give readers this option; if anything, they flatten our views of intimacy rather than letting us expand them through imagination.