Bernard Taper dreamed about Raphael's "Portrait of a Young Man,'' the most prized painting looted by the Nazis that has never been found. He spent two years searching for the Raphael in ravaged post-World War II Germany -- and for many other works he did recover -- as an art-intelligence officer with the Monuments, Fine Arts and Archives section of the U.S. military.

"It's the most valuable single thing that's still missing,'' says Taper, a longtime writer for the New Yorker, one-time Chronicle reporter and retired UC Berkeley journalism professor. He tracked down many artworks in 1946 and '47, including objects German peasants had looted from an abandoned train carrying booty pilfered by Luftwaffe chief Hermann Göring. A connoisseur of luxury, Göring had amassed thousands of paintings, sculptures and others works during his tenure as the second-most powerful man in Nazi Germany.