Dark Are the Steps of Time - Paperback

All but one member of the Mammoth Cave Wild Cave Tour led by Keven goes missing. Officials say they are just lost in the cave. Bob and Walt know better. When Bob and Walt go to find the tour, they suddenly find themselves in familiar passages, but virgin, or almost virgin, cave. What follows is a tour through Mammoth Cave as it once was as they struggle to get the cavers home.