The Crustlings (Paperback) (ISBN-13: 9781496985798)

The Crustlings is about a group of friends who win an adventure weekend. While cave-diving, a storm breaks out above them. With the weight and pressure of the water, the cave system collapses, sending the friends deep into the centre of the earth and a subterranean world, where they join the local inhabitants in a series of amazing adventures over crystals to bring peace back to the subterranean world where life began.