In this conclusion to the Jackaby series, the eccentric detective and his assistant Abigail Rook find themselves in the middle of a war between magical worlds.

An evil king is using a blend of magic and technology to push Earth and the Otherworld into a mortal competition. In New Fiddleham, Jackaby and Abigail are caught in the middle as they try to close the rend between the two worlds, and discover why zombies are appearing around town. As the romance between Abigail and the shape-shifting police detective Charlie Cane deepens, Jackaby's feelings for 926 Augur Lane's ghostly lady, Jenny, begins to deepen. Can they defeat an evil that wants to destroy the future altogether?