An upper-middle-class prole novel about the Chicago Democratic Convention week riots in 1968 when Mayor Daley's pigs bloodied up the yippies and hippies in Lincoln and Grant Parks. The novel's tenor is part James T. Farrell, part Dos Passos, part Steinbeck's In Dubious Battle. The four main rivers of the title are the lives of an ex-Communist organizer from the '30's who now manages a socialist movie house; an ad man going through an alcoholic identity crisis who's turned into an honest man by the hippies; two young lovers caught up in the bloodtide, who are the victims; and two dumb cops -- clubswingers on a headbopping field day. While the novel moves along with occasionally bright dialogue, and the characters (aside from the fiends in blue) have a vague appeal, nothing rises above the stereotyping. You know absolutely everything that'll happen just by the casting, and it does.