Harriet Lane’s books are delectably chilling, but labeling them “thrillers” is a disservice. Her brand is subtle and sly. Readers who live for big twists may find themselves disappointed.

“I think that there are clues all the way through [Her] that the ending isn’t going to be a big, showy, jazz hands reveal,” says Lane. “I’m not at all interested in stitching it all up neatly for my readers. I like an engaged reader, and that’s the sort I write for: someone who wants the clues and wants to assemble their own answer.”

To its intended audience, Her poses a vexing question: What could be the nature of an acquaintance that means so much to one person and seemingly nothing to another? Twenty years after they first meet, Nina and Emma are living in the same north London neighborhood. When Nina discovers Emma at the park, pregnant and parenting a toddler, it steals her breath.

“I’m scared of seeing her, and I’m scared that I’ll never see her again,” Nina confesses in Her.

Nina doesn’t reveal herself to Emma that day. When she does, Emma doesn’t recognize her at all. Nina has built an enviable life—she’s a chic, successful painter with an undemanding spouse and teenage daughter—and yet she’s stewing over Emma’s relatively beleaguered existence as a full-time caregiver for her young family.

“Are you enjoying it, Emma? I find myself thinking as I unscrew the cap from the tube of purple madder and squeeze a shiny worm of pigment onto a saucer. Is your life the one you were due?” Lane writes.

Lane, who lives in north London with her husband and two children, enjoyed life as a successful journalist, writing and editing for the likes of the Guardian, the Observer, Vogue and Tatler, until 2008. Then, over the course of two spring days, she began to lose her sight—entirely, in one eye.

“I just knew that I had to part with journalism, because at that point I was freelancing, and with freelancing, you have to be superreliable and dependable, and I just wasn’t any of those things, because I was always in MRI scanners,” she says.

It took two years to get a firm diagnosis: a rare autoimmune disorder requiring lifelong medication to maintain her remaining vision.

“I’m losing my sight, I’m losing my own s ense of independence, my confidence in the future, my career and the sort of status that had come from that, my own sense of self,” she says. “I also lost this enormous sense of pleasure from sitting down in a room, when you’ve got all the information, and creating a story. And that’s why I found myself fumbling into fiction.”

Lane’s first novel, Alys, Always, published in 2012, is the story of Frances, a middling magazine editor, who uses her status as the sole witness of a fatal car crash to transform her life in arguably unethical ways. Like Her, it’s a fastidious, fraught and utterly compelling look at a female psyche that’s somehow slightly...off.

In Her, Nina manages to exceed Frances in insidiousness: She returns Emma’s wallet when it’s lost at the grocery store. She returns another of Emma’s important possessions when it, too, goes missing. And she parlays these interactions into an unlikely friendship.

In alternating chapters, Emma interprets these events as bright coincidences, spots of good luck. That she is unquestioningly susceptible to Nina’s overtures may be attributed, at least in part, to the fact that she’s drowning in domesticity—“all this buttoning and unbuttoning,” she notes, quoting a famous suicide note—and desperate to be seen, and appreciated, for who she once was.

Nina is scheming to oblige. “She looks at me as if she recognizes me, the real me. It’s a shocking moment. For a second I’m scared I’m going to cry with the relief and horror of it,” Emma marvels.

Sans judgment, Lane explores the difficulties of mothering young children. “There are elements of my own experience of having small children, moments that were so powerful and so isolating, and I remember at the time looking and looking for books that would echo my own experience. Maybe I wasn’t looking in the right places—I didn’t find those books,” she says.

From Emma’s vantage, Nina’s reality—grown child, posh home, thriving career—is a world away. Invited over for lunch one day, she becomes bewitched by one of Nina’s canvases hanging in the uncluttered living room.

“I’m thinking about how wonderful it must feel to make something like that, how satisfying; and to my horror I find my eyes are filling with tears. Partly it’s amazement, I realize, and partly it’s because the landscape seems somehow immediate and familiar, personal in a way that good art can be; but mostly it’s envy. An incredulity that she is free to do this. And that she can,” Lane writes.

Nina wants Emma to look; she wants her envy. She wants something penitential, and she won’t rest until it’s extracted. And the motivation for all her manipulation will prove to be something Emma would never suspect.

“The conventional thing would have been something horrific...but that doesn’t necessarily feel true. I think that, actually, the things that shape [who you become] as an adult can often be spun out from tiny, easily forgotten moments that no one else would notice,” Lane says.

Whether inhabiting Emma’s openness or Nina’s scheming, Lane relishes the opportunity to explore alternative perspectives.

“Writing Emma was in some ways cathartic, but the Nina moments are just so delicious, you know? It’s fun to write these bad people—don’t ask me why,” Lane says. “Sometimes the ability to switch out of all the dreary stuff—laundry, picking everyone up from school, and then there’s always the background hum of the autoimmune thing—into someone’s else’s reality, even if that reality is quite dark, is a huge privilege. It feels good.”

Megan Labrise is a freelance writer and columnist based in New York.