The Dire King by William Ritter, 344 pages

The fate of the world is in the hands of detective of the supernatural R. F. Jackaby and his intrepid assistant, Abigail Rook. An evil king is turning ancient tensions into modern strife, using a blend of magic and technology to push Earth and the Otherworld into a mortal competition. Jackaby and Abigail are caught in the middle as they continue to solve the daily mysteries of New Fiddleham, New England — like who’s created the rend between the worlds, how to close it, and why zombies are appearing around. At the same time, the romance between Abigail and the shape-shifting police detective Charlie Cane deepens, and Jackaby’s resistance to his feelings for 926 Augur Lane’s ghostly lady, Jenny, begins to give way. Before the four can think about their own futures, they will have to defeat an evil that wants to destroy the future altogether.

I'm heartbroken that this is the final book is this series. It had me on the edge of my seat, and the ending had me royally pissed off. All in all, a great read.