An Instant #1 New York Times bestseller
People Magazine's Book of the Week
Bookish's "Must-Read Books of Winter"
Cosmopolitan's "2019 Books to Bring to Your Book Club"
Bookbub's "Biggest Books of Winter"
Crime Reads' "January's Best Psychological Thrillers"
USA Today's "5 New Books Not to Miss"
When Jessica Farris signs up for a psychology study for women ages 18-32 conducted by the mysterious Dr. Shields, she assumes she'll answer a few questions, collect her money, and leave. But as the questions grow more intense and invasive and the sessions include demands about what to wear and how to act, Jess imagines that Dr. Shields may know what she's thinking - and what she's hiding. As Jess's paranoia grows, she can no longer distinguish between her real life and Dr. Shields' manipulative experiments. Caught in a web of deceit and jealousy, Jess learns that some obsessions can be deadly.