There was a time when there were four worlds, each pulsating with magical power and connected by a single city: London. After a desperate attempt to prevent the corruption and ruin of the four Londons, only three remained standing: Gray London, prosperous but barely able to remember its magical heritage; Red London, rich and powerful, ruled in recent times by the Maresh family; and White London, abandoned to brutality and decadence. Now the worlds are going to collide again, drawn to the edge of a dangerous precipice by the discoveries of three extraordinary magicians. First there is Kosika, the girl queen of White London, who has fed her city on blood and dreams, and whose growing devotion to both is leading her down a dangerous path. Then there's Delilah Bard, a thief who was born in Gray London and crossed the worlds to become a legend far away. She's a famous magician, a cunning heroine, and a reckless scoundrel all at once. After disappearing in search of a new adventure, she is forced to return to a dangerous port to join some old friends who need her help more than they imagine. And finally there is Tes, a young runaway with a powerful and unusual ability, who hides in Red London while she tries to stay out of the spotlight. Tes is the only one who can prevent the worlds from falling apart, if she manages to survive first.