Zoe Ziakas enjoys a quiet life, working as a librarian in her quaint New England town. When a mysterious black book with an unbreakable latch is delivered to the library, Zoe has a strange feeling the tome is somehow calling to her. She decides to consult the Museum of Literature, home to volumes of indecipherable secrets, some possessing dark magic that must be guarded.

Here, among their most dangerous collection, the Books of Dubious Origin, Zoe discovers that she is the last descendant of a family of witches and this little black book is their grimoire. Zoe knows she must decode the family's spell book and solve the mystery of what happened to her mother and her grandmother. However, the book's potential power draws all things magical to it, and Zoe finds herself under the constant watch of a pesky raven, while being chased by undead Vikings, ghost pirates, and assorted ghouls.

With assistance from the eccentric staff of the Books of Dubious Origin department--including their annoyingly smart and handsome containment specialist, Jasper Griffin--Zoe must confront her past and the legacy of her family. But as their adventure unfolds, she'll have to decide whether or not she's ready to embrace her destiny.