It was the largest moving object on the face of the earth, but for Carolyn and Peter Hardin it was a towering wall of steel bursting out of a squall at full speed, bearing down on their ketch Siren.  In a few compressed moments Siren was shattered by the indifferent bulk.  Struggling for his life, Peter Hardin had two memories burned into his brain--the hand of his wife being torn out of his frantic grip and the huge white letters on this supertanker's stern as it steamed away--Leviathan.