Aisling Keane is an investigator with the secretive spy organization known as Dragonfly. Thrust unexpectedly into the field, she and her mechanical dragon partner are surrounded by danger and intrigue.

Aisling thought she'd been hired to be a secret agent-then found that Dragonfly required new recruits, even skilled witches like her, to prove themselves. One clue leads to the next, and she's assigned to work with Lance Stone on a mission. Small crimes herald larger ones, and the larger ones suggest a mysterious organization lurking in the shadows. When an ally turns into an enemy, Dragonfly has to send a new agent into the field. The mission is simple: infiltrate, discover, and escape. But in the secretive world of international crime, nothing is ever really simple. And simple never meant easy.

Fortunately, Aisling's newest creation of technology and magic—a mechanical dragon about the size of an eagle—has just been improved by her infomancer coworker and given a cutting-edge artificial intelligence. Cait's little sister will need all the help Shimmer can provide. Despite the workload, she'll still need to find time for family and her coven. A danger is on the horizon, and the coven's guardian is worried. Will it get in the way of Aisling's new job? The investigator-turned-agent wouldn't have it any other way.