A seemingly healthy woman with a transplanted heart suffers from acute respiratory distress and dies on the New York subway. Jack Stapleton, a medical examiner and a character frequently appearing in Cook's novels, does the autopsy and suspects that the death could be due to a flu-like virus. While investigating the mysterious heart transplant of the dead woman, he finds out a larger conspiracy. He meets Wei Zao, a Chinese billionaire businessman who holds a double Ph.D. in molecular biology and genetics. Further cases of flu-like virus get reported in many other parts of the world and Jack determines to stop the pandemic from spreading.