Mackenzie Casper is a strong student, but what people know her for is her mother, a bestselling thriller writer with a worldwide following. When her mother dies in an accident, the fans grieve publicly and the investigators start asking whether it was an accident at all.
On the day of the memorial, Mackenzie receives an envelope signed "From #1 fan. XOXO." Inside are pages from her mother's diary, beginning: want to know a secret? Love, Mom. A second envelope follows, and a third.
Mackenzie starts investigating on her own and finds that the family has been living around something for years. Iliana Xander builds the book on what her mother did on the way up, who else knew, and the possibility that it eventually caught up with her.