A Hoboken housewife slowly comes to realize that her husband is the serial killer who's terrorized lower Manhattan and New Jersey. This isn't The Lodger; there's never any doubt for us that Zelly Wyche's solitary electrician husband Pat is the man who's raped and murdered five blond women over the past six months, the man whose rambling, musically-obsessed letters to the police have earned him the sobriquet the ``Symphony Slasher.'' In these terms the story sounds positively silly, and there's an undercurrent of unintentional humor in first-novelist Hunter's self-important attention to the details of an outdoor New York concert that somehow includes both chamber and symphonic music. But Hunter works so close to the minds of her characters that the story's improbable details yield to an authentic sense of nightmare. Zelly, who can't believe the evidence that distant Pat fits every detail of the killer's profile, takes her baby daughter and runs away to her mother's house, then allows Pat to take her home. Meanwhile, John Nassent, grieving over his sister's murder, seeks out Madeleine Levy, who survived the Slasher's assault. Confirmed by Madeleine in his determination to hunt down the Slasher and kill him, sensitive John ends up cruising the transvestite haunts of the West Village for another witness who can identify the Slasher. The murder plot is shrilly melodramatic, and Pat's abused background is far too simply invoked to make him a compelling killer. Even so, there's much to admire here among the tormented figures of innocents forced to confront their most dreaded fears about their intimates and themselves.