A call from a distraught wife, and another from Lt. Murphy of the Chicago PD Special Investigation Unit makes Harry believe things are looking up, but they are about to get worse, much worse. Someone is harnessing immense supernatural forces to commit a series of grisly murders. Someone has violated the first law of magic: Thou Shalt Not Kill. Tracking that someone takes Harry into the dangerous underbelly of Chicago, from mobsters to vampires....

Camden, North London. A tangled, mangled junction of train lines, roads and waterways. Where minor celebrities hang out with minor criminals and where tourists and moody teenagers mingle. In the heart of Camden, where rail meets road meets leyline, you might find the Arcana Emporium, run by one Alex Verus. He won't sell you a wand or mix you a potion, but if you know what you're looking for, he might just be able to help.

For 1000 years, the people of Alera have united against the aggressive races that inhabit the world, using their unique bond with the furies - elementals of earth, air, fire, water and metal. But now, Gaius Sextus, First Lord of Alera, grows old and lacks an heir. Ambitious Lords manoeuvre to place their Houses in positions of power, and a war of succession looms on the horizon. Far from city politics in the Calderon Valley, young Tavi struggles with his lack of fury crafting.

Since time immemorial the Spires have sheltered humanity, towering for miles over the mist-shrouded surface of the world. Within their halls aristocratic houses have ruled for generations, developing scientific marvels, fostering trade alliances, and building fleets of airships to keep the peace. Captain Grimm commands the merchant ship Predator. Fiercely loyal to Spire Albion, he has taken their side in the cold war with Spire Aurora, disrupting the enemy's shipping lines by attacking their cargo vessels.

In his acclaimed Codex Alera novels, best-selling author Jim Butcher has created a fascinating world in which the powerful forces of nature take physical form. For millennia, the people of Alera have used their unique bond with these elementals for protection. Now, as enemies become allies, and friends become bitter foes, a danger beyond reckoning looms . . . .