A New York Times bestselling spine-tingling novel of medicine run amok by master of medical suspense Robin Cook...Two graduate students decide to solve their financial problems by becoming egg donors at an exclusive, highly profitable fertility clinic on Boston’s North Shore. But second thoughts and curiosity prompt the two women to find out more about their donated eggs. Obtaining employment at the clinic under aliases, they soon discover the horrifying aims of its research, immediately putting their lives—and their sanity—irrevocably at risk...