Makayla and her two friends, Tanner and Andrew, have no recollection of their visit to Agartha, let alone their unfinished business there. Will a hostile action by an unrecognized man, who makes a surprise appearance in Brownsville, be enough to unlock their memories? Will they have to start completely from scratch, knowing only the information that got them to Agartha in the first place? 

With Mammoth Cave under heavy surveillance, the trio will be forced to find a new entrance to Agartha. What adventures, civilizations, beasts, and beings await Makayla and her friends as they try to set things right?