As World War II ended, one of its most terrifying weapons had yet to be unleashed.

#1 New York Times bestselling author Brad Thor and New York Times bestselling author Ward Larsen serve up their signature “high-caliber suspense that keeps the pages flying” (Publishers Weekly, starred review) with this chilling new thriller rooted in one of the darkest secrets of World War II.

When two American archaeologists vanish while live-streaming an expedition deep in the jungles of Indonesia’s Halmahera Island, their final footage triggers a classified US intelligence alert dormant since 1945.

DIA bioweapons expert Dr. Sara Taylor and CIA operative Alex Ross are sent to investigate. What they uncover is no ordinary ruin, but a sealed WWII-era installation tied to Imperial Japan’s notorious Unit 731, a top-secret Nazi scientific program, and a forbidden series of wartime experiments erased from history.

But before Sara and Alex can determine what they’re dealing with, the site is breached by a powerful organization operating beyond the reach of any government—one intent on reshaping the global balance of power on its own terms.

What begins as a mission to rescue two missing Americans quickly becomes a race to stop a weapon hidden at the end of World War II from bringing civilization to its knees.