In Boring, Ore.-born Los Angeles writer Madeline Stevens' debut novel, Devotion (Ecco, 292 pages, $26.99), sexual and class tensions merge into riveting drama, as a nannying gig for a broke, 20-something college dropout turns into something more intimate—and perhaps more sinister.

When we first meet Ella, the nanny and protagonist, she's seducing an off-duty cop in her Crown Heights neighborhood—though it's never explicitly stated, Devotion's clearly set at least a decade ago, before Crown Heights was littered with wine bars and liberal arts grads—in hopes he will buy her dinner. Since leaving the rural Oregon of her youth, dropping out of college and coming to New York, Ella's barely made ends meet, bouncing around from one dead-end job to another.

Her luck seems set to change when a young, wealthy couple, Lonnie and James, hire her to look after their infant son. James works in finance, and Lonnie, she claims, needs time to write. In reality, Lonnie spends most of her time tooling around with the baby and Ella, who quickly grows infatuated with her. She marvels at a childbirth scar on her employer's body—as if something so perfect could experience any sort of rupture.

But there's resentment at play, too. Ella is an aspiring writer herself, albeit one without the resources to spend long days procrastinating from writing. Her writerly eye turns invasive, taking notes on Lonnie's journal, her upbringing and her secret affair with James's friend, Carlow. As their lives become increasingly enmeshed, Ella comes to realize that Lonnie's world isn't so whimsical and carefree as she previously believed. In many ways, she has even less autonomy than Ella.

While the plot is, on its face, a fairly straightforward narrative about a love triangle—or quadrangle—and a misfit infiltrating high society, Stevens uses the plot as a lattice on which to weave issues of representation in modern media, particularly women's bodies. Lonnie's paramour, Carlow, is a photographer, and while modeling for him, Ella muses on his work: "Most of the bodies he looked at were chopped up and genderless. I wondered if that's what he wanted to do to my body."

The dark side of devotion runs throughout the book: In addition to her preoccupation with the constituent elements of Lonnie's body, Ella also finds herself dwelling on horror films and a grisly set of murders in her neighborhood. In less skilled hands, these could come off as digressions, but Stevens manages to weave everything together into a meta-commentary that never detracts from the surface story. As far as debut novels go, Devotion is about as promising as they come.

GO: Madeline Stevens talks with Kevin Sampsell at Powell's Books on Hawthorne, 3723 SE Hawthorne Blvd., powells.com, on Thursday, Aug. 22. 7:30 pm.