An elite scientific military force must combat a plague beyond any cure—a scourge that turns all of nature against mankind in this nail-biting new thriller from James Rollins, the #1 New York Times bestselling author of the Sigma Force series.

From the depths of the Indian Ocean, a horrific plague has arisen to devastate humankind – unknown, unstoppable...and merely a harbinger of the doom that is to follow.

Operatives of the shadowy covert organization Sigma Force, Dr. Lisa Cummings, and Monk Kokkalis search for answers to the bizarre affliction aboard a cruise liner transformed into a makeshift hospital. But a sudden and savage attack by terrorist hijackers turns the mercy ship into a floating bio-weapons lab.

Time is an enemy as a worldwide pandemic grows rapidly out of control. As the seconds tick closer to doomsday, Sigma's commander, Gray Pierce, must join forces with the beautiful assassin who tried to kill him – following the trail of the most fabled explorer in history into the terrifying heart of an astonishing mystery buried deep in antiquity and in humanity's genetic code.