As a Judge for the administrators of the Codex Magica, Calico Shivers makes life-and-death decisions about wizards gone bad... then carries out the sentences. But nothing in his career has prepared him for his next assignment: termination of a wizard who time travels, creates monsters for fun, and skateboards to his evil-wizard lair. During an epic battle of magic and mundane munitions, Shivers is cast back to the 19th century American Old West, a time and place with limited magic, deep-seated prejudices, and no flush toilets.

Shivers rides into Geyser Falls, a town beset by beings out of myth and legend and run by a smirking sheriff who mistakes Shivers for a real judge of the legal variety. Shivers's first trial involves a blue-haired, free-spirited witch sent back in time by the rogue wizard.

In no time at all, Shivers is mired in murder, deceit, and treachery, all complicated by a tribe of angry cannibals with a grudge against the people of Geyser Falls. The future looks very grim for misplaced wizards of the 21st century, and Shivers is caught between protecting the beleaguered townspeople and the need to get back to his own time.