Murder by Chance

Give Dennis credit for coming up with perhaps the unlikeliest sleuth ever to tackle an impossible crime, and for setting the whole affair in locked bathroom on a tour bus. Betty Chance is in her fifties and struggling to make ends meet after a perfect storm of painful developments. Her husband left her for "an older, fatter woman" who could cover his gambling losses and, in addition to feelings of be-trayal, her ex- left her his debts which gutted their savings. After a year, Chance manages to pull her-self together to start a business, Take A Chance Tours, which runs gambling junkets. One such routine trip, to Moose Bay, Minnesota, turns deadly when one of her passengers is found stabbed to death in the vehicle's lavatory. When her driver%E2%80%94an ex-con who improbably served a full 10 years for an acci-dental convenience store stickup%E2%80%94becomes the prime suspect, Chance turns Jessica Fletcher to exon-erate her. There's nothing memorable about the characters, the prose, or the plot, and the attempts at injecting humor won't work for all readers. (Mar.)