An insatiable, unstoppable beast, the wildfire called Jackknife has already devoured 17,000 acres of California's Lassen Volcanic National Park. A devastating force of nature, it has brought out the very best -- and worst -- in those sworn to defeat it.

Ranger Anna Pigeon is among the exhausted firefighters, serving as medic and spike camp security, when an abrupt weather shift sends Jackknife racing relentlessly in their direction. And when the monstrous blaze has passed, Anna emerges from her protective shelter to discover two men are dead: one a victim of the hungry flames, the other stabbed through the heart. Now, trapped in a nightmarish landscape of snow and ash, cut off from rescue by a rampaging winter storm, Anna must investigate an inexplicable homicide -- as she and nine others struggle to survive the terrible rage if nature. . . and the murderer in their midst.