Reading a John Grisham thriller is a lot like sitting down near a big bowl of Chex party mix: The stuff isn't that good, but for some reason it's hard to keep your hands off it.
Grisham's latest salty snack, a tasty, nonnutritious, and ultimately unsatisfying page-turner called The Last Juror, begins in 1970, when 23-year-old Willie Traynor moves to Clanton, Miss., and buys the rinky-dink Ford County Times for $50,000 borrowed from his grandmother. Willie is a party boy and college dropout, but he sees a chance to redeem himself: The Times has been used primarily as a vehicle for fawning obituaries and stories about tea parties, but Willie, who is both ambitious and idealistic, plans to make a fortune by turning it into an instrument of social justice. Anyone want to bet the forces of evil will try to scuttle his dream?
Grisham fans will recall that gossipy, racially divided Clanton was the setting of his top-notch first novel, ''A Time to Kill.'' As in that book, this one revolves around a particularly heinous and lurid rape: Shortly after Willie takes over the paper, a pretty young widow named Rhoda Kassellaw is sexually assaulted in her bedroom while her children look on, then stabbed to death. She lives just long enough to theatrically whisper the name of her killer: ''Danny Padgitt. It was Danny Padgitt.''
The Padgitts turn out to be a powerful local clan whose members seem to emerge from their swampy compound only to rape, kill, or bribe public officials. They practically own Clanton's corrupt sheriff and have evaded the law for decades, liquidating anyone who dares to tread on their turf. Brash and cocky, Willie sees his chance to right some historic wrongs, and he goes after Danny in the pages of the Times, before, during, and after Danny's melodramatic cliff-hanger of a trial, which is the centerpiece of the book. The Padgitts, of course, go after Willie -- and just about everyone else who gets in their way, threatening even members of the Kassellaw jury.
Alas, instead of developing the threat posed by the sinister Padgitts -- which would have made the action scary rather than hammy -- Grisham chooses to explore, at length, Willie's wholesome and rewarding relationship with one of the jurors, a saintly old black woman named Calia Ruffin. The estimable Mrs. Ruffin cooks him pork chops and banana pudding, and worries about the state of his soul. As a human being, you rejoice for Willie; as a reader, you may fall asleep. Grisham seems to be losing interest in the genre he basically reinvented. Over the last few years, he has interspersed his slick legal thrillers with earnest and sentimental novels like last year's ''Bleachers.'' Here, he seems to be trying to combine the two, with an unfortunate result: a hung jury.