Unknown to the human race, a group of aliens has set up a colony deep under the ocean. The world's bestselling master of the medical thriller, Robin Cook skillfully combines human drama and high-tech thrills with the latest breakthroughs and controversies of modern medicine. Now, in his most daring novel yet, a mysterious transmission from the bottom of the Atlantic Ocean leads a crew of oceanographers and divers to a phenomenon beyond scientific understanding - a discovery that will change everything we know about life on Earthhellip;