It's a volatile world: waves of magic and technology fight and feed off each other, monsters prowl the streets, werebears, cats, hyenas stalk their prey, and Masters of the Dead 'pilot' blood-starved vampires with their minds.

In Atlanta, lives Kate Daniels, former mercenary, Knight of the Order of Merciful Protection, world class swordswoman and smart-mouth, and – recently – mate to Curran, the Beast Lord of Atlanta's Pack. His problems are now hers, and this one is particularly heartrending – many of the Pack's shapeshifting children can't control their beast nature and are doomed to perish.

A medicine can help – but it's controlled by the European shapeshifters, who've proposed a devil's bargain to Kate and Curran: In return for the medicine, they must arbitrate a thorny dispute...which promises to send them straight into a deadly trap...