The gripping new action thriller from New York Times bestselling author and former FBI agent Noah Boyd. Steve Vail has brains, brawn and balls – and is back for his latest mission. Steve Vail visits Kate Bannon, Assistant Director of the FBI, for a well-earned and romantic New Years Eve in Washington, DC, but he suddenly finds himself knee-deep in a very complicated and unusual case. A man known simply as Calculus, an intelligence officer at the Russian embassy, approaches the FBI claiming he knows of several Americans who are supplying confidential government information to the Russian secret service. In exchange for this list, he asks for $250,000 for each traitor the FBI arrests. But when Calculus is suddenly recalled to Moscow, the Bureau suspects the worst. The Russians have probably captured Calculus, and might have access to his list – which means they'll soon track down the informants and murder them. That is, unless the FBI can find them first, but without knowing exactly who is on the list, they must keep the operation quiet. Once again, Vail is their man. He's the ideal candidate for this kind of stealth recon mission. It soon becomes clear that finding Calculus and his list of traitors isn't going to be quick or quiet. In fact, it's going to be downright deadly…