I WAS almost eleven when I first learned of my maternal grandfather’s existence.

My mother, my stepfather, my five-year-old brother, and I lived in a sunny three-room tenement in Brooklyn, New York. The walls of our foyer were lined floor to ceiling with my mother’s books, and I read as many as possible, entering a trancelike state in which everything else floated on the edges of my awareness. My mother had substituted curtains for the missing doors on all the rooms, allowing voices to drift through the narrow apartment. One Saturday in 1954, I was reading in the bedroom when I became aware of my mother’s voice rising and my father shushing her. (I never thought of him as a stepparent, since he was the only father I’d ever known.) Minutes later my mother called me into the kitchen. I marked my page with a bookmark and pushed past the curtain.