Luke Green and Foyer's Folly

Luke Green is an average boy. While playing with his friends at their tree house in the woods they are forced to undertake a journey into an underwater world that will change their lives. There are things beneath the ocean waves that those living on the surface could never imagine. Unfortunately for these children, all of the worst of those things seem to be intent on making their lives difficult.As they try to survive in this dangerous and alien world their only hope of returning to their parents is blocked by a powerful group led by a very powerful man. Oh, and then there is the megaladon...