Born of an Anglican mother and a Jewish father who disdained religion, Kaplan knew little of her Judaic roots and less about her famed great-grandfather until beginning her research, more than twenty years ago. Shedding new light on Gordin and his world, Kaplan describes the commune he founded and led in Russia, his meteoric rise among Jewish New York's literati, the birth of such masterworks as Mirele Efros and The Jewish King Lear, and his seething...