India Steele is desperate. Her father is dead, her fiancé took her inheritance, and no one will employ her, despite years working for her watchmaker father. Indeed, the other London watchmakers seem frightened of her. Alone, poor, and at the end of her tether, India takes employment with the only person who’ll accept her–an enigmatic and mysterious man from America. A man who possesses a strange watch that rejuvenates him when he’s ill.

Librarian Sylvia Ashe knows nothing about her past, having grown up without a father and a mother who refused to discuss him. When she stumbles upon a diary that suggests she's descended from magicians, she's skeptical. After all, magicians are special, and she's just an ordinary woman who loves books. She seeks answers from a member of the most prominent family of magicians, but she quickly learns that finding the truth won't be easy, especially when he turns out to be as artless as her, and more compelling and dangerous than books.

When Gavin travels to Edinburgh with his good friend Oscar Barratt, he’s eager to acquire a centuries-old book on witchcraft for the soon-to-open Glass Library. Even with ruthless railroad magnate John J. Defoe in the bidding, the victory comes easily. Perhaps too easily. Hours later, the book is stolen. A single clue links the theft to the recent abduction of two women, both magicians.

Leonora Spencer has an acquaintance with death. Sixteen years ago, only she survived the brutal murder of her family. Now, as an assistant in her uncle's London morgue, she uses her photographic memory to catalogue details for his coroner reports. She also isn't opposed to helping him during postmortems if his skilled hands begin to shake. After a thief breaks into the morgue and steals a locket from a young woman's corpse, Leo is determined to understand why, even if it means going against Detective Inspector Jasper Reid's express orders to keep her nose out of it.

December 1899. After the death of her beloved grandmother, Cleopatra Fox moves into the luxury hotel owned by her estranged uncle in the hopes of putting hardship and loneliness behind her. But the poisoning of a guest on Christmas eve throws her new life, and the hotel, into chaos. Cleo quickly realizes no one can be trusted, not Scotland Yard and especially not the hotel’s charming assistant manager.