If ""vanished"" conjures up visions of Great Unsolved Mysteries, prepare to be disappointed: most of the 20-odd stories covered here, like some 97 percent of similar cases in Canada, involve missing persons who were eventually ""located."" But--crime fans, take heart--""located"" does not necessarily mean being round alive and well. Take spirited 32-year-old Grace Todd, for example, who failed to return to her job at a Toronto insurance company in August, 1971, after a two-week camping vacation with her (somewhat dim and oafish, Grace's friends would say) husband David. Grace had left him for another man, explained David, who then changed his own lifestyle and began hanging out with the teenagers who congregated at the pool where he worked as a guard. The kids had carte blanche to use David's apartment and raid the refrigerator. But not the deep-freeze, which was taped shut. . . . Sometimes these matters take a while to unravel, as in the case of Arthur Kendall, who stabbed his wife to death, buried her, and see terrified his children (who knew the truth) that they clammed UP for nine years before finally talking to the police; the body was never found, but Arthur was convicted. Prefer unsolved mysteries? ""Curiouser and Curiouser"" is an appropriate chapter title for Murdoch's summary of the disappearance of British Columbia mushroom-grower (and, said the police, mushroom-based hallucinogen manufacturer) Arthur Williams, who vanished in 1977 while piloting his light plane in poor weather, and that of his wife, who turned up missing about a year after her husband was declared legally dead. Williams had often boasted that he knew how to fake his own death but, if he did se, why? And why did his wife leave over $50,000 in cash in the house when she disappeared? In addition to these and other individual mysteries, Murdoch also devotes seine attention to general categories such as missing children (where police know that ""the full facts are seldom voluntarily offered"") and the identification of bodies. In spots a bit gory for the weak-stomached, but diverting for dyed-in-the-wool crime buffs.