Emma Carpenter lives in isolation with her golden retriever Laika, house-sitting an old beachfront home on the rainy Washington coast. Her only human contact is her enigmatic old neighbor, Deek, and (via text) the house’s owner, Jules. One day, she reads a poorly written—but gruesome—horror novel by the author H. G. Kane, and posts a one-star review that drags her into an online argument with none other than the author himself. Soon after, disturbing incidents start to occur at night.

Ana and Reid needed a lucky break. The horrifically complicated birth of their first child has left Ana paralyzed, bitter, and struggling: with mobility, with her relationship with Reid, with resentment for her baby. That's about to change with the words any New Yorker would love to hear—affordable housing lottery. They've won an apartment in the Deptford, one of Manhattan's most revered buildings. Reid dismisses disturbing events and Ana’s deep unease and paranoia as the price of living in New York—people are odd—but he can't explain the needle-like bite marks on the baby.

Lee Gulliver never thought she’d find herself living on the streets—no one ever does—but when her restaurant fails, and she falls deeper into debt, she leaves her old life behind with nothing but her clothes and her Toyota Corolla. In Seattle, she parks in a secluded spot by the beach to lay low and plan her next move—until early one morning, she sees a sobbing woman throw herself into the ocean. Lee hauls the woman back to the surface, but instead of appreciation, she is met with fury.

The rundown rental house didn’t seem so bad at first. But now, someone is stealing her food. Rattling her bedroom doorknob. Digging through her belongings. Each night brings more disturbing incidents. And each night, Nya is more convinced that it’s not an intruder. She suspects the culprit is hiding in plain sight: her peculiar roommate-of-necessity, Sidney.

Best friends Lindsey, Kendra, and Dani endure every parent’s nightmare when a tragic accident befalls their teenage boys, leaving one dead, another in a coma, and a third too traumatized to speak. Reeling from the worst night of their lives, the three mothers plunge into a desperate investigation of the bizarre incident. How could something so horrible happen in their wealthy Southern California suburb? They soon discover that the accident was just the beginning, and troubling discoveries lead to chilling questions: Do they really know their children? Do they even know each other?