What if the ground beneath your feet was not made of solid earth and stone, but had been hollowed into hundreds of tunnels and passageways? What if there were mysterious forces in these tunnels, mere inches below you as you sit in class or eat a banana? What if it were up to just two kids to stop these forces? And what if the fate of the entire town rested on your shoulders?
When Catalina Catalan presses a silver handle into the hillside and opens a doorway to the underworld, Granite know that he will have to follow his brave and extraordinary friend. Can they save the town and emerge as heroes?