In a world where vampires dominate and werewolves are despised, a teenaged half-vampire discovers his recessive werewolf genes are developing with the approaching full moon.
In her alternate England of 1851, while taking her friend Sidheag by train to her werewolf pack in Scotland, sixteen-year-old Sophronia uncovers a plot that threatens to dissolve all of London into chaos and must decide where her loyalties lie once and for all.