In the Yellowstone backcountry, a merciless source of evil carries a torch for the past…Petra Dee and her immortal husband, Gabe, have been trying to gain a toehold in what passes for ordinary life in Temperance, Wyoming-a wickedly enchanted land founded generations ago by the alchemist, Lascaris. Petra may be adept when it comes to the uncanny, but as a reasoned geologist, Petra still can't fathom the wildfires suddenly engulfing Yellowstone National Park, or why Gabe claims to have seen the sky explode in flames. The answers could lie in the past. It was a dreadful night in 1862 when Lascaris went harvesting for souls, only to be set upon by townsfolk determined to eliminate the root of all evil in a trial by fire. Petra can't help fearing that Lascaris has crawled out of the ashes of history to wreak vengeance-and to complete his mission by claiming every vulnerable soul in Temperance. With the help of Gabe and her coyote sidekick, Sig, Petra must now venture into Lascaris's shadow before he turns her world into an inferno burning out of control.
