AstroWolf, LaserShark, SmartHawk, and StinkBug are ready for a new mission to find a planet fit for human life after we've finally made Earth unlivable. When they splash-land on the Water Planet, they find power-hungry clams, a rebellious underwater force, and a world full of too-good-to-be-true. Can this aquatic world really be humans' new home? And why are these clams so eager to swap planets?