A coming-of-age and falling-in-love story that turns into a war story: a tour de force that reaches from the last golden summer before the Great Depression into the darkest precincts of the twentieth century.            In 1929, at an international youth summit in the Weimar Republic, four young Americans meet various German counterparts on a lovely, remote mountaintop; here they talk earnestly late into the night, quarrel, fall in love and find themselves drawn into political ideals and intrigues that will soon engulf Europe and plunge the world into mayhem. And the fates forged then envelop them again in 1944, when Ingo Miller is running a failing German restaurant in Washington, D.C., and Marty Panich is pushing pencils for the Roosevelt administration. Childhood friends now estranged, they are suddenly reunited when their old friend Isaac Tadziewski--a runaway from Brooklyn back then, and now caught up in the bloody Polish resistance--obtains incendiary information about the Final Solution. The fourth, Sammy Butler, a left-wing journalist riding into the Reich with the Red Army, also learns of Issac’s discovery and embarks on a shadowy quest of his own.            So begins a journey from the confusions of youth into the chaos of war: for Sammy, the horrors of the Eastern Front; for Ingo and Marty, a hastily organized mission that lands them in liberated Yugoslavia and pushes on into Silesia, not far from a place that featured in their Weimar adventures, w