Sequel to: Rising tiger

"In the war-ravaged borderlands of Ukraine, a Russian military unit has gone rogue. Its members, conscripted from the worst prisons and mental asylums across Russia, are the most violent, dangerous combatants to ever set foot upon the modern battlefield. As they move from village to village, they meet little resistance as all able-bodied men are off fighting the war. When multiple American aid workers are killed, America's top spy is sent in to settle the score. But in a country almost the size of Texas, will Harvath be able to find the men in question and, more importantly, will he be able to stop them before they can kill again? --,Back cover