Immortal Descendants are disappearing and seventeen-year-old Clocker Saira Elian is next on the list... Saira and Archer's romantic London summer is shattered by the bold kidnappings of Immortal Descendants. It's clear Mongers want control of the Descendant Families, and when they target a powerful Shifter, there's no doubt they will eliminate anyone who stands in their way. A split in time could be the cause of this new Monger aggression, and Saira, Archer and Ringo suspect their time-traveling nemesis Bishop Wilder. One dangerous world is exchanged for another when Saira and her friends track Wilder to the gloomy streets of Paris in 1429. They find the city besieged by marauding wolves led by a fanatical peasant girl who will be known to history as Joan of Arc. Crossing the time stream to repair it has dropped them into the heart of the Hundred Years' War on the eve of an epic battle, where the line between friends and enemies will be drawn in blood. To finally end the deadly game of cat and mouse with Wilder, Saira must confront her greatest challenge yet: the truth about her changing Nature.