From the highest skies to the deepest oceans- this is the gist of the new challenges facing the X-VENTURE Xplorers! Fresh from sky scrapping in the previous book, they now need to contend with the ocean’s many denizens- some of which put the giants of land and sky to shame. Giant carnivorous 'dolphins', massive prehistoric crocodiles and what may be Nessie's great(X10) grandmother are just a few things that hinder (or maybe help) the team seek the true KING OF THE SEAS!