A taut, electrifying thriller." —Brad Thor, #1 New York Times best-selling author of Edge of Honor Military aide Luke Steele and FBI Special Agent Amberlyn Reiner go undercover once again to unravel a string of murders that may be tied to a nuclear threat capable of igniting a war. Military aide Luke Steele grapples with self-doubt after a tragic loss during his last mission. But when a trusted American journalist is killed in Istanbul, Luke must push past his grief to prepare for a new assignment. The Turkish police report the journalist as the eighth victim of a serial killer. But US intelligence considers the suspicious death a murder at the hands of an international threat and fear that the journalist could have had top-secret information that is now in the hands of an enemy of the United States. The president tasks Luke to join with FBI Special Agent Amberlyn Reiner to investigate. As the two delve into the cause of the journalist’s death, they unravel a conspiracy that reveals a chilling plan for the assassination of the president and a potential nuclear strike on the United States. Going undercover as a couple, Luke and Amberlyn travel to Istanbul to connect with a Russian source who holds key information to the case—if they can find him in time. In the crucible of danger, Luke must rediscover his confidence and trust the bond he has forged with Amberlyn as they fight to save the president of the United States and stop a perilous nuclear plot poised to kill millions.