Lydia Millet's new novel has the bones of a thriller — there's a woman threatened by a stalker ex-husband and a kidnapped child. But "thriller" implies high action, and "Sweet Lamb of Heaven" is softer and more emotionally interior. But "psychological thriller" doesn't work, either: The term leaves little room for the loopy, music-of-the-spheres philosophizing its heroine engages in. We didn't know we needed a metaphysical thriller, but here Millet is with a fine one.

She's well positioned to pull off such a feat of genre-breaking. In her 2013 novel, "Magnificence," she moodily contemplated broken relationships and our animal nature, while in 2014's "Mermaids in Paradise" she turned our assumptions about marital commitment into an offbeat comic romp.

This time the setup is equally peculiar, if eerier. Anna, the narrator, has split from her narcissistic husband, Ned, after the birth of their daughter, Lena. Anna's pregnancy revealed Ned's selfishness, but it also heralded the arrival of a thrum of voices in her head, details on "single-celled organisms, hockey scores, feather on dinosaurs, celebrity suicides."

For Anna, her brief status as a walking Wikipedia is more troubling for the way it sets her emotionally adrift than for any medical issues it suggests. "Joan of Arc had heard a voice advising her to help raise the siege of Orleans," she says. "But as far as I could tell the voice had no specific instructions for the likes of me."

Odder still, Anna and Lena are drawn unheeded to a New Hampshire community of people with similar experiences. But her efforts to play detective on her own brain have to compete with more urgent troubles: Ned wants her back to play the good wife in photo ops as he runs for office. When she resists, her life, and Lena's life, are imperiled.

"Sweet Lamb of Heaven" answers the question of how Anna will deal with Ned. But the bigger question hanging over the novel — the reason for all those rattling voices and that oddly magnetic community — is what larger forces govern our existences. Millet, like Anna, is obsessed with "the background orchestration of the deeper language, an urge that underlies our patterns of survival."

If that sounds a little too New Age-y, there's plenty of "House of Cards"-style scheming going on. But Millet is also a master of capturing feelings of paranoia in a host of ways, from family to our health to our information-soaked world. Politics are just one way we're manipulated, and the creepy pleasure of the novel is in Millet's suggestion that we're in a constant struggle to gain a sense of control.

Mark Athitakis is a reviewer in Phoenix.