Someday the rabbi will leave? Yes, and that day may be soon--now that nonreligious tycoon Howard Magnuson has become president of the congregation at Rabbi David Small's coalition temple (Orthodox/Conservative/Reform) in Barnard's Crossing, Mass. Besides being generally bossy, you see, Magnuson wants his daughter Laura to be married by a rabbi--even though her groom is a non-converting non-Jew: handsome, vacuous John Scofield, a WASP-y candidate for State Senator. (Laura's his Svengali-ish campaign manager.) Then, while the Magnuson/Small feud seems to be leading--via a nasty conspiracy--to the rabbi's dismissal, Rabbi Small finds himself getting interested in a local hit-and-run homicide case: the accused is a Jewish college-student who (despite the evidence) seems to be innocent; the victim is a shady Boston-politics errand-boy. Could there be some connection between Rabbi Small's problems at the temple--and this Mt-and-run (which just might be murder)? There could indeed: Kemelman does a dandy job of revolving three or four subplots around until they all fit together--a bit too neatly, perhaps, but quite engagingly. So, though the dialogue is (as usual) rather stiff, with orthodox-ish Rabbi Small more preachy and unyielding than ever (lots of theological lecturing), this Kemelman outing should please his fans even more than the weaker Thursday the Rabbi Walked Out (1978)--thanks to lively temple wrangling, an appealing spread of characters, and a brightly unconventional plot.