In April of 1925, the Honourable Daisy Dalrymple Fletcher, now mother to two-year-old twins, has decided to resume her journalistic career, and for her first piece she's agreed to write about the Tower of London, the royal fortress and compound of buildings that includes the infamous Bloody Tower. Daisy is not only given a tour of the Crown Jewels, she interviews and observes the Yeoman Warders, and meets the Raven Master, in charge of the Tower's legendary ravens. But most important she's been invited to observe the centuries-old Ceremony of the Keys ritual. Because the complex is locked and guarded during the ceremony, Daisy will have to spend the night -- her first away from her babies -- at the Tower.