Almost 140 years ago, Noah Simmons was killed in the Hoyo del Diablo of the Arizona desert. Now, after years of haunting his lonely cave, he watches a group of settlers arrive...Scientist Liz Madison and arrogant geologist Ethan Winslow enter into a marriage of convenience so Liz can join the BioCave experiment. Living as husband and wife, Liz and Ethan fight against an attraction neither wanted. Liz begins to sense a presence - and Noah appears with a warning. Liz is confused but she knows that they must fight for the survival of their newfound happiness.