For years No. 8 Schleichstrasse was like any other house on the suburban Bonn hillside called Venusberg. Everything was always spick-and-span, and from the kitchen came the odor of Bavarian stew. No. 8's occupant, a chubby, rumpled man with pink bulging face and bulging briefcase, went to the office each morning, returned each evening, like so many hard-working businessmen of the district.
One morning last week a sleek black Mercedes limousine with official license plates glided up to the curb; the chauffeur nodded amiably to the plainclothes policeman who had taken up station on the sidewalk during the night. Both beamed...