A rogue spy weaves a deadly web of intrigue in this pulse-pounding World War II espionage thriller from the bestselling author of The Kremlin Letter.   A man with many names moves through the shadows of war-torn Europe. Known to most as "the Shadowboxer," he is a spy and an assassin, the scourge of the Nazi high command. Courageous and highly skilled, he sneaks in and out of the most heavily guarded concentration camps, liberating select prisoners.   To those he sets free, the motives behind the Shadowboxer's actions hardly matter. But leaders of the Third Reich and Soviet Intelligence officials are desperate to determine what game the lone wolf agent is playing, and what his missions mean for the fate of postwar Germany. In the high-stakes realm of international espionage, information is the most valuable prize of all, and no secrets are bigger than those kept by this mysterious operative. But when he discovers his role in a massive conspiracy that could cost the lives of thousands of Allied soldiers, the Shadowboxer has no choice but to step into the light.   A powerful tale based in the grim realities of covert operations, The Shadowboxer brims with suspense and nonstop action. Intricately plotted and disturbingly authentic, it cements Noel Behn's reputation as one of the twentieth century's most original and convincing spy novelists.