Septimus Heap is stolen by a midwife the night he is born, and she pronounces him dead. That same night, the baby's father, Silas Heap, comes across a bundle in the snow containing a newborn girl. The Heaps take her in, name her Jenna and raise her as their own Who is this mysterious baby girl, and what really happened to their beloved son Septimus?

Pulled through a glass that brings him back in time, Septimus Heap becomes the apprentice of an alchemist.

Wolf Boy is sent on a Task by Aunt Zelda, while Septimus and the dragon, Spit Fyre, fly off to bring their friends home, but they all wind up on an island whose secrets are as dangerous as its inhabitants.

Septimus must battle the remnants of the Dark Domaine, which will remain until the power of the evil Two-Faced Ring is destroyed forever. To accomplish that, the ancient Alchemie Fyre must be relit, a task that sends Septimus to the very origins of Magyk and Physik.