You can now get your hands on Robert R. McCammon's The Wolf's Hour for only 1.99$ here. It's considered one of the best werewolf novels ever written!
Here's the blurb:
Master spy, Nazi hunter—and werewolf on the prowl—in occupied Paris: A classic of dark fantasy from a Bram Stoker Award—winning author. Allied Intelligence has been warned: A Nazi strategy designed to thwart the D-Day invasion is underway. A Russian émigré turned operative for the British Secret Service, Michael Gallatin has been brought out of retirement as a personal courier. His mission: Parachute into Nazi-occupied France, search out the informant under close watch by the Gestapo, and recover the vital information necessary to subvert the mysterious Nazi plan called Iron Fist. Fearlessly devoted to the challenge, Gallatin is the one agent uniquely qualified to meet it—he’s a werewolf. Now, as shifting as the shadows on the dangerous streets of Paris, a master spy is on the scent of unimaginable evil. But with the Normandy landings only hours away, it’s going to be a race against time. For Gallatin, caught in the dark heart of the Third Reich’s twisted death machine, there is only one way to succeed. He must unleash his own internal demons and redefine the meaning of the horror of war. From the award-winning author of Swan Song and Boy’s Life, this is a “powerful novel [that] fuses WWII espionage thriller and dark fantasy. Richly detailed, intricately plotted, fast-paced historical suspense is enhanced by McCammon’s unique take on the werewolf myth” (Publishers Weekly).