The Kill Switch

They are Sigma Force's secret weapon . . .

From bestselling masters of action and intrigue James Rollins and Grant Blackwood comes the first in an unparalleled new thriller series based on the Sigma Force novels, featuring former Army Ranger Tucker Wayne and his partner, military working dog Kane.

Tucker Wayne and Kane are recruited by Sigma Force to extract a Russian pharmaceutical magnate from Siberia. A scientific genius, the man holds the biological key to a new weapon system, a danger engineered from the ancient past to terrorize the modern world. From the frozen steppes of Russia to the sun-blasted savannahs of Africa, Tucker and Kane must piece together a mystery going back to the origins of life on Earth--before the ancient peril can destroy the heartland of America, and with it, the world.