Sorrel is the unruly daughter of the heads of the Mage Council, protectors of the secret realm of the Mage Pocket, where libraries float through the sky, cats turn invisible, and sunlight is magic.

Theo is the reluctant apprentice of the Dark Mage, the terror of the Mage Pocket, waiting in the shadows for her chance to act.

When her parents die in a house fire, Sorrel refuses to believe it's an accident. Theo knows it's not, because he saw his mentor do it. He helped his mentor do it. He's still haunted by the smell of smoke.

Sorrel is bent on finding answers, but that will require learning some complex magic. Theo is trying to break his magical apprenticeship contract, but that will require a lot of research.

Together, they form an unlikely alliance-Theo will teach Sorrel to Cast, Sorrel will help him research. But both are keeping secrets, and neither one knows the other's true identity. As their friendship grows, so do the consequences of discovering the truth.