In the mountains of Washington state, in sight of Mount Rainier, an idealistic neighborhood called Greenloop has been created. Although it sounds like the perfect eco-friendly community, its creators, Tony and Yvette, have done little planning to ensure that the circle of homes is truly self-sufficient and can thrive if temporarily cut off from the rest of the world.

When Mount Rainier erupts, the ugly truth emerges: the residents of Greenloop are trapped. They’re safe from the blast, but lahar – a boiling mix of mud, water, pyroclastic material, and boulders – blocks the only road out of the neighborhood. Their cell phones don’t work, and there is no landline or radio to contact the gridded world. There will be no more drone deliveries of groceries and sundry – in fact, the most no-nonsense member of the community, a stocky, no-nonsense older woman called Mostar, insists on cataloging the food in her household and that of a young couple, Dan and Kate, that she’s befriended, and helps them start a secret garden in their garage.  When neighbors ask Dan for assistance – he’s become the local handyman – Mostar insists he be paid in food that’s been catalogued by Kate.

But starvation isn’t what the residents of Greenloop have to fear – it’s the tall apelike creatures that are spotted on the outskirts of the settlement. Residents scoff at the possibility that the creatures might be Sasquatches or Bigfoots, despite the enormous footprints they leave behind and the havoc they cause – they insist the creatures are bears or some other large mountain creature. But Kate comes face-to-face with one on her back deck, and she knows it’s a Sasquatch. And she’s terrified.

Max Brooks has written Devolution in the same format he wrote World War Z – he toggles back and forth between interviewing a national park ranger, scraps from news articles or broadcast interviews, and excerpts from Kate’s diary.  He lays out a harrowing tale that will haunt readers long after they’ve finished the book, and they might never want to enter a forest again.