The dashing wizard Felix Harrowgate has reclaimed his sanity, magic, and position in society. But even as he returns to his former place in the Mirador-the citadel of power and wizardry-there are many who desire his end. Mildmay the Fox is an ex-assassin, a cat-burglar, and Felix's half-brother. Tied to Felix by blood and magic, Mildmay goes where Felix goes-even into the Mirador. There, Mildmay finds himself drawn to an alluring spy of the Bastion, a rival school of wizards.

The Bastion desires above all else to bring down the Mirador, and Felix is the key to its destruction. But Mildmay cannot let Felix stand alone, and will fight to save both his brother and his city from certain ruin.