Hidden Society (Hidden Society #2)

A new series from Rafael Albuquerque and Rafael Scavone, the team behind Neil Gaiman's A Study in Emerald! After assembling the last stand between humanity and a primeval world-killing serpent god, Ulloo the wizard leads the heroes of the Hidden Society to Europe where they must stop a group of nihilist warlocks from waking the serpent beast from the bowels of the earth.