It was the morning after the best party ever, the tumult and joy that marked the fall of the Berlin Wall on Nov. 9, 1989. After 28 years, East Berliners were giddy with marvel that they could now visit the West.

Günter Taubmann felt different, as if, he said, “I am in the wrong movie.” Eight years earlier, his only child, Thomas, had been killed trying to cross the wall, one of 138 people who died at the barrier erected by the Communists in 1961 to stop Germans streaming out of the poor, repressive East.

Now, someone at work had been to the West and back during that magical night, and was telling the tale. Mr. Taubmann’s Communist colleagues professed to be exultant over the end of the order they had long espoused. Workmates who had not mourned Thomas at the time of his death were suddenly solicitous.