The NEW YORK TIMES bestselling author returns with a gripping, high-concept adventure thriller in the Sigma Force series – for fans of Dan Brown and Michael Crichton.A remote military research station in Utah sends out a frantic distress call, ending with a chilling final command:Kill us all!By the time help arrives every living thing for fifty miles has been annihilated. And blight is spreading.To halt the inevitable, Commander Gray Pierce and Sigma must unravel a threat that rises out of the distant past, to a time when Antarctica was green and life on Earth balanced on a knife edge. Following clues from an ancient map rescued from the lost Library of Alexandria, Sigma will discover the truth about an ancient continent, about a new form of death buried under miles of ice, and the coming extinction of mankind.