Fifty Christmasses ago a 15-year-old boy and his father slipped into the nerve centre of the West German government, dispensing presents of wine and cognac to the doorkeeper and the caretaker.
In the darkness they walked together through the half-deserted corridors, stopping to look in on the cabinet room and the few senior officials who were still at their desks on Christmas Eve. It was one of their last happy shared memories.
Sixteen months later the father, Günter Guillaume — the right-hand man to Willy Brandt, the country’s hugely charismatic chancellor — was arrested and convicted of spying for East Germany’s secret police, the Stasi.
