"Getback" is prison slang for revenge, and this funny first novel contains a long string of them, culminating in a spectacular, climactic finale. Narrator "Flat Store" (prison "handle" of Humbert James Barker) tells how convicted bankrobber Conroy ("Mother Superior") transforms the lives of the misfits and losers in cell 3-J-5, McNeil Island Penitentiary, Puget Sound, Wash. Mother sets up a scheme to develop the "outside" skills of his eight "cellies" and make them rich through illegal horse-racing bets. Along the way, he pulls off a series of inside getbacks against a corrupt warden and his murdering lieutenant. Eventually, Mother gets a new trial, his cellies are released, and outside getbacks snag a banker, a judge, an assistant U.S. Attorney, even a Senator.