In two olive-drab paperbacks, guidebooks to the cultural monuments of Brussels and Berlin, published by Seemann Verlag and costing three marks each, I glimpsed Hitler the aspiring Frontsoldat-cum-artist. The Berlin guide has Hitler's signature in faded purple ink on the inside front cover, with the place and month of purchase: "Fournes, 22 November 1915." In the Brussels guide Hitler simply scrawled "A. Hitler" in pencil; the last three letters trail downward like unspooling ribbon. A chapter on Frederick the Great is especially worn, its pages tattered, marked with fingerprints, and smeared with red candle wax. Tucked in the crease between pages 162 and 163 I found a three-quarter-inch strand of stiff black hair.