Gutsy California p.i. Kinsey Millhone ("A "Is For Alibi, etc.) has taken on the job of finding the killer of pregnant teen-ager Jean Timberlake, in the town of Floral Beach, 17 years ago. Bailey Fowler was convicted of the murder, escaped from prison a year into his sentence, and built a respectable life--only to be tripped up by a fluke 15 years later. Now he's claiming to be innocent, and his cancer-ridden father has hired Kinsey to find evidence to support that claim. Meanwhile, Bailey's mother Oribelle is a self-pitying diabetic; his sister Ann, a school-guidance counselor, now tends her parents and helps run the motel that is home and business for the family. Kinsey stays there while she finds and talks to old contacts of Jean Timberlake--who was illegitimate, promiscuous, out of control, and hellbent to discover her father's identity. Kinsey has unproductive interviews with Shana, Jean's tarty, near-alcoholic mother; high-school principal Dwight Shales; oily Baptist pastor Bob Haws; and Dr. Joseph Dunne and his forbidding wife Elva, among others. There are also more killings before Kinsey--after an out-of-character move that artificially prolongs the denouement--confronts the murderer and just misses becoming another victim. Intriguing plot; swift pace; convincing, mostly repellent characters; seedy, small-town ambience; and a heroine who has mellowed just a little make this another winner for Grafton.