A blend of lyrical memoir and sober history, The Glassmaker's Son recounts a son's decades-long quest to uncover the world his father left behind in Nazi Germany. Along the way, he makes a series of surprising discoveries about his family, who were important players in the Bavarian glassmaking industry. After his grandfather was forced to sell the family villa, for instance, the Nazis turned it into their regional headquarters before it was destroyed by American artillery in the closing days of the war. In another twist, the author recovers a pair of lost portraits of his great-grandparents that an elderly housekeeper had been "guarding" for more than 40 years.

Using a cache of old letters found in his parents' attic and other documents, Kupfer painstakingly pieces together the details of his grandfather's deportation and murder at Theresienstadt, a concentration camp in western Czechoslavakia touted by the Gestapo as a "spa town" for distinguished Jews. At its core, this book is about a search for identity - the identity of the author's soft-spoken, inscrutable father and of the author himself.