New York Times #1-bestselling author Robin Cook takes on the cutting-edge world of gene modification in this pulse-pounding medical thriller.

When a young, seemingly healthy woman collapses suddenly on a New York City subway car and dies upon reaching the hospital, her case is chalked up to a virulent strain of influenza. That is, until she ends up on veteran medical examiner Jack Stapleton's autopsy table, where Jack discovers some striking anomalies: First, that the young woman has had a heart transplant, and second, that her DNA matches that of the transplanted heart.

After two other victims succumb to a similar rapid death, Jack fears the city is facing an unprecedented pandemic. But the facts aren't adding up, and now Jack must race against the clock to determine what kind of virus can wreak such terrifying havoc. But when his investigation leads him into the fascinating realm of CRISPR/Cas9, a gene-editing biotechnology that allows animal DNA to be inserted into living human cells, he'll uncover the dark underbelly of the organ-transplant market...and come face-to-face with a megalomaniacal businessman willing to risk human lives to fulfill his dreams of conquering a lucrative new medical frontier. And if Jack's not careful, the next life lost might be his own...