After rescuing Lilliana, who was being auctioned off by her husband in a small country village, Atlas Catesby must work to help her to clear her name after the husband is found murdered.

"An explosive return to the library leaves the six Alexandrians vulnerable. Old alliances fracture as the initiates take opposing strategies as to how to deal with the deadly bargain they failed to uphold. Those who remain with the archives wrestle with the ethics of their astronomical abilities, while elsewhere, an unlikely pair from the Society partner to influence politics on a global stage. And still the outside world mobilizes to destroy them....

"London, 1815. Amateur sleuth Atlas Catesby is about to discover the dark side of the bright lights. His long-awaited night at the opera with Lady Lilliana ends abruptly when a notorious courtesan is shot to death in Covent Garden. The infamous victim was the mistress of the powerful Marquess of Vessey. Atlas believes that the marquess--his former brother in law--is responsible for the long-ago death of Atlas's sister, Phoebe. Atlas seizes the opportunity...