Blossom

Vachss ( Flood ) is not for everyone, but fans of his hard-hitting series about Burke, the tough ex-con who mercilessly tracks criminals and degenerates down to society's seamiest depths, will find this fifth installment as riveting as his previous thrillers. The Burke novels read almost as one continuing story, with enough references to previous events and characters to leave the new reader, if not baffled, at least feeling on the outside looking in. Even more discomfiting is the fact that Vachss comes close to rendering the term ``hard-boiled'' obsolete. Many scenes are uncomfortably graphic and intense in themselves; their cumulative effect is extraordinarily powerful. This time, Burke leaves behind the familiar New York underworld and his band of street ``brothers'' when a former cellmate's call for help takes him to a small Indiana town where the ex-con's nephew has been charged with a series of sex murders. Burke must determine if the boy is guilty and, if he isn't, locate the real killer. Like all Vachss's novels, this one is named after its central female character, here, an enigmatic waitress who turns out to be as tough and deadly as Burke himself. A New York attorney specializing in child abuse cases, Vachss is responsible for some of the grittiest crime fiction written today. (June)