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...