A man with no memory washes ashore during a deep ocean storm. But is he a man? His feet and fingers are webbed, he can breathe underwater and he swims like a fish. A military supercomputer takes all the data and posits a guess that he is possibly the last citizen of Atlantis. For now, he agrees to help the marine scientist who saved his life, Dr. Elizabeth Merrill, at the top secret Foundation For Oceanic Research.