Judeth Cole has always had certain uncanny abilities. But when she arrived at Solidago, her grandfather's estate by the sea, she was forced to keep them secret. There she lived a harsh life under his rule and the haunting legacy of her late grandmother, Aurelia. Until the fateful day she ignited a fire with her magic. It was the last time she saw her family alive.

Seventeen years later, she's living in Seattle as Jude Clark, and failing at life, when she makes a last detour through her favorite bookstore, selecting a book to read as she waits to die. But when she pulls it from the shelf, an invitation to her for a clandestine midnight meeting slips out. Jude is quickly swept up into a world of secrets and magic, discovering a circle of powerful new companions led by the mysterious, enigmatic Arla. The source of their magic, Arla tells her, is an entity, trapped and bound, that they call The Fathom. But Jude swiftly realizes Arla wants this power all to herself, and that she's willing to kill for it.

Terrified, Jude turns to Levi, the handsome bookseller who's seen her at her worst. With his help, she begins a research journey that leads her all the way back to Solidago, the house she swore to never return to. Now, the Fathom threatening to break free and Arla on the hunt, Jude must finally face her past to save her future.