Forty years ago, the Gather family—James, his daughter Beau, and his son Billy—vanished during a whitewater rafting trip and were presumed dead. Five years later, Billy reappeared on the far side of the world, telling an impossible tale of a primordial valley populated by dinosaurs, aliens, Neanderthals, and androids. Little Billy became the punchline of so very many jokes, until he finally faded from the public eye.
Now, a group of graduate astronomy students follow their professor, Noah Barnes, up a mountain for what they believe is a simple stargazing trip. But they’re about to travel a lot farther than they planned. Noah (the now grown Billy Gather) has finally figured out how to get back to the valley. Accidentally bringing his students along with him, he’s confident he can get everyone back home, safe and sound. But the valley is a puzzle—one it turns out Noah hasn’t figured out, and they’ll need to solve it together if there’s any chance of making it out alive.
