Hudson Greer and his caving partner, Jett, are determined to become teen legends who discover a long-sought passageway that connects two giant cave systems in their little mountain town. But they're haunted by the history of a giant sinkhole that opened up and swallowed the town's fully-packed church, steeple and all. Dozens were killed, including Hudson's grandfather. Hudson knows it's in danger of happening again; he just doesn't know when or where. Can his caving instincts and science knowledge predict or prevent the next disaster? Are the shoddy logging practices of the town's main employer tempting fate? And who's on whose side when business and political shenanigans mix with evaded environmental codes?

Nothing less than the lives of the townspeople are at stake - and it's up to Hudson to separate myth from fact, and get key players working together, before it's too late.