After private detective Harper Blaine "dies" for two minutes, she realizes that she has become a greywalker, able to live in the human world, but also able to enter the crossover zone, where otherworldly creatures live.
Bounty hunter Rachel Morgan is the best at finding otherworldly creatures who break the law. After clashing with the head of the Inderland Runner Services, Rachel quits and finds herself on the run with a price on her head.
Vanessa, who has always had the special power to become invisible, discovers that she and her best friend Catty, a time-traveler, are goddesses of the moon who must fight together to overcome the evil Atrox.
After the suspicious death of her mother in 1895, sixteen-year-old Gemma returns to England, after many years in India, to attend a finishing school where she becomes aware of her magical powers and ability to see into the spirit world.
Soon after steeplejack Joe Clarke begins work on one of the spires of Muncaster's medieval cathedral, terrible things start to happen and Joe realizes that there is a malevolent force connected to the spire's gargoyle.
As Thaniel, a wych-hunter, and Cathaline, his friend and mentor, try to rid the alleys of London's Old Quarter of the terrible creatures that infest them, their lives become entwined with that of a woman who may be either mad or possessed.