The book centers around the molecule called CRISPR/Cas9, which can be custom-tailored to find and alter genes in living organisms.

[1][2] 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.

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.