This complex fourth book of the Dog Days series finds San Francisco magic enforcer Mason along with his dog Lou, a magical familiar known as an Ifrit, taking a job tracking the whereabouts of a missing woman. She is suspected of stealing an ancient magical tome full of spells capable of opening pathways to different worlds and recreating this one. Spells that powerful are bound to attract a lot of interest so practitioners of black magic are hot on the trail, complicating things for Mason and Lou. As a sinister plot begins to emerge, Mason calls for reinforcements and even their combined power may not be enough to save magic, the world or themselves from what is taking shape off the San Francisco coastline.Levitt’s usual fast pacing, tight plotting and well-developed characters keep this series strong. There are plenty of twists to keep readers on their toes while the interaction between Mason and Lou remains as engaging as ever. The melancholy ending leaves considerable room for further development as readers wonder, what’s next?