Tom and Kaz go on a topsy-turvy adventure when they look for Sarah and Peyton in Kirvak Mound (a series of caverns within Skeleton Springs). They soon discover that the effects of Kirvak Mound has de-aged Sarah to a little girl and aged Peyton to an old man. They now have to evade prehistoric creatures to find their way back. When they look for Sarah, they find other portals leading to various points in history. It is later revealed the portals in Kirvak Mound also show possible futures of Perim, including one where it is totally submerged.
