December 1960. Thirteen year old Jenny Harper is exploring the caves with her brother Bill and their best friend Mike. They see a strange shimmering light up ahead. Bill rushes ahead, disappears around the bend. Fade to present day. Thirteen year old Jack and his twelve year old sister Amanda visit their Grandma Jenny in the mountains over the Christmas holiday. They hear the story of a mythical cavern that Grandma went searching for fifty years earlier...