Hoffman's latest and bleakest work--the third in his Small Worlds cycle (Small Worlds, 1996; Big League Dreams, 1997)--continues the saga of the disciples of the Krimsker Rebbe in the darkening years of the '30s and '40s. The duo of the title are a pair of offstage characters whose depredations can spell only disaster for the now-scattered Jews of Krimsk. In the first of the novel's two parts, it is Rosh Hashanah 1936, and Rabbi Finebaum's own son-in-law, Hershel Shwartzman, is a worker in the sinister arts, a colonel in the NKVD whose primary duty is the torturing of political prisoners. But Grisha, as he's known, begins to suffer his own loss of faith as it dawns on him that the wheels of death he helps to run will inevitably grind him up also. As fear displaces zeal, he is drawn into the kind of self-examination that can't help but lead to his demise. The second (and shorter) narrative is set on Yom Kippur 1942 and reintroduces two of the major characters from Small Worlds: Yechiel Katzman, once the Rebbe's prize pupil, banished for apparent heresy, and Itzik Dribble, the sweet-natured retarded boy who was an integral part of that earlier novel's climax. Now, both are in the clutches of the Nazi killing machine: Katzman, an inhabitant of the Warsaw Ghetto, is on a train to Treblinka; Itzik, who has grown to immense size and strength, is an uncomprehending tool of the SS. A master of the art of getting into his characters' heads, Hoffman creates intricate and thoroughly convincing monologues. And he hasn't lost his taste for the miraculous nature of the everyday, a fascination that makes him one of the logical heirs to the legacy of Isaac Bashevis Singer.