A chilling, eerie novel about a criminal psychologist whose interview with a serial killer has an unexpected effect on her relationship with her unnerving stepdaughter

Criminal psychologist Seonkyeong receives a surprising call one day. Yi Byeongdo, a serial killer whose gruesome murders shook the world, is willing to break his silence and speak exclusively to her. Intrigued, Seonkyeong agrees to interview him.

That same day, Seonkyeong’s husband brings home Hayeong, his eleven-year-old daughter from a previous marriage. Hayeong has been living with her grandparents since her mother’s mysterious death, and now her grandparents have been killed in a house fire.

Seonkyeong is determined to make the child feel at home, but to her husband’s frustration she finds it difficult to connect with the child who says little and acts strangely. It’s not long before Seonkyeong notices similarities between her stepdaughter and Yi Byeongdo: they both look at her with cold eyes, each possessing an unnerving calmness that hides a fierce, cruel temper.

As Seonkyeong begins to question details of Hayeong’s past—and as her relationship with Yi Byeongdo grows more complex—she begins to wonder what her young stepdaughter is truly capable of.

Written with exquisite precision and persistent creepiness, Sleep Well, Mommy is a captivating horror thriller from one of Korea’s most renowned authors.