When a San Francisco film professor named Aryeh goes to a bar and hears a middle-aged German-born playboy complacently recalling the WW II shooting of 40 civilians, he says: ""Tonight I talked to a man who killed Jews for the one and plain and simple reason that they were Jews. And relished it! Goddam it, he relished it, and I've got to do something about it!"" So Aryeh and four equally garrulous friends decide to make the German ""feel as if he's walking around wearLng a yellow Star of David, not knowing what's going to happen to him""; they do this with a series of practical jokes patterned on the Ten Plagues that Moses and Jehovah sent down on Egypt. Blood (squirted all over the German's car), frogs (set loose under the German's seat at the opera), hail (rock salt all over the German's house), etc. About halfway down the list of plagues, however, the German catches on and starts fighting back--with blood, aphids, and poison oak. And finally the good guys kidnap the German and almost--but only almost--kill him. Puerile premise (the Holocaust meets Animal House) and--despite first-novelist Cohen's intrusively erudite references to films and music--amateurish execution.