Ancient diseases encoded in the DNA of humans wait like sleeping dragons to wake and infect again--or so molecular biologist Kaye Lang believes. And now it looks as if her controversial theory is in fact chilling reality. For Christopher Dicken, a virus hunter at the Epidemic Intelligence Service, has pursued an elusive flu-like disease that strikes down expectant mothers and their offspring. Then a major discovery high in the Alps --the preserved bodies of a prehistoric family--reveals a shocking link: something that has slept in our genes for millions of years is waking up.

Now, as the outbreak of this terrifying disease threatens to become a deadly epidemic, Dicken and Lang must race against time to assemble the pieces of a puzzle only they are equipped to solve--an evolutionary puzzle that will determine the future of the human race . . . if a future exists at all.