The youngest of eight children, Stephen J. Dubner grew up in a family that was industrious, rambunctious, and, above all, Catholic. His parents were true believers, their faith extending to every corner of their lives. But they were also Jewish converts.

Only when he reached his twenties did he discover his parents' extraordinary story, a story full of bitter estrangements, hard-fought triumphs and deep secrets (Ethel Rosenberg, executed as an atomic spy in 1953, was his mother's first cousin). In excavating the story, he felt the tug of the religion his parents had abandoned and began to pursue it as vigorously as they had pursued their adopted faith.

Along the way, he met dozens of his own Jewish relatives, traveled to his grandparents' shtetl in Poland, wrestled with the implications of the Holocaust, re-created the life of his late father, and saw his relationship with his mother curdle so thoroughly that it would fall to the Archbishop of New York, John Cardinal O'Connor, to help broker a peace.