In a change from delightful Margaret Benton, his usual sleuth (Deadly Climate, etc.), Barth now introduces another senior-citizen charmer--shabby Russian ÇmigrÇ Jakob Barzeny--a chess genius who takes on all comers at McArdle's chess club in Westchester. A regular there is furniture-salesman Leo Perkins, a nice guy struggling to pay for things like the mortgage and daughter Amanda's piano lessons. The girl's teacher is suave minor celebrity Harman Parrish, who, it turns out, dabbles in a lot more than music. When he's found murdered in his lush apartment, Leo, a victim of circumstance, is charged with the killing by not-too-bright Lieutenant Rucker. Out on bail--strangely provided by Barzeny--Leo and his canny savior launch their own investigation and produce a surprising culprit in a lively if overextended finale. Brisk, warmly unpretentious entertainment.