It is June 21, the longest day of the year, and the life of new mother Camilla is about to change forever. After months of maternity leave, she will drop off her infant daughter at daycare for the first time and return to her job as a literary agent. Finally. But when she wakes, her husband Luke isn’t there, and in his place is a cryptic note. Then it starts. Breaking news: A hostage situation is developing in London. The police tell her Luke is involved—but he isn't a hostage. Her husband—doting father, eternal optimist—is the gunman.