A far more conventional caper than The Costume Party (p. J-124)--but also featuring that good-humored bear, now on a bicycle, and those three trusty chickens, now on roller skates. They're off to deliver a cake to ""a sick little bunny named Billy""; and along the hilly, rainy, obstacle-strewn route, just-about-everything happens to the cake and to its deliverers. When they arrive at Billy's house akimbo, and then take a monumental spill besides, he laughs--for ""the first time. . . in months,"" says Mrs. Rabbit happily. The bear and the chickens, pleased with themselves (and paid for the cake), head hack to the bakery and, they're confident, kudos from ""the boss."" There's a winning geniality about this, along with very deft drawing--would only that Park had material of a caliber to match his talents.