When college student Coral pulls up in front of an Idaho cave in her brother’s RV, all she has in mind is a spelunking adventure. The last thing she expects, as she clambers out of the vehicle, is to see a billowing black cloud in the southeastern sky. She’s smart enough to realize it can’t herald good tidings, so she hurriedly crams all her food & water into her backpack and races into the cavern, just ahead of the first blast of searing hurricane-speed wind. The heat drives her further and further into the cave, until the blackness surrounding her matches the faraway entrance into the sooty, roasting landscape she can no longer see.

After nearly a week, the temperature drops enough for her to venture out … into a silent, charcoaled world. Nothing has survived the mysterious scorching — wood ash heaped on stone foundations, stripped hulks of melted metal at intersections, human bones buried in cinders along the road. She plods for days through the gray, eerie stillness, all the time wondering: what happened? Where did this this inferno originate? Is she the only survivor?

Finally, in a small river town, Coral encounters a big, bearded man who quietly materializes out of the permanent dusk. Benjamin survived the firestorm much like Coral — he burrowed into a cellar with a water tank — and now lives in the basement of his home, but both realize their limited food & water supply will eventually force them to muster out. As the summer temperatures plunge and sooty snow begins to fall in this sunless world, moving on together, they decide, is the safest, and sanest, path forward.

As they search for food, shelter, and the distant dream of a safe new home, Coral & Benjamin encounter the raging, raucous, rambling remnants of humanity, now more feared than welcomed. As they approach Boise and a rumored settlement at the University of Idaho, they cautiously anticipate a safe landing zone. However, in this post-apocalyptic world, nothing is as it seems in the frigid, colorless wilderness.