In Through Divided Minds (1988), N.Y.C. psychologist Mayer reported warmly on his work with sufferers of multiple personality disorder (MPD); here, he writes an equally compassionate account of his treatment of multiples possibly created by satanic cults. Cheesy chapter titles--``Education in Evil,'' ``The Slasher,'' ``The She-Satan,'' etc.--belie Mayer's humane approach to his hot-potato subject, which first surfaced in his life a few years back when, under hypnosis, a young MPD patient screamed, ``Don't kill the baby! Please! Don't kill the baby!''--and went on to describe how as a tyke he had been forced to do just that during a satanic rite. After a second multiple, Rebecca, told a similar story, Mayer realized that he had to ``change [his] thinking. To take a harsher view of the world and human nature...to understand evil''--which led him to in-depth research on Satanism, well summarized here, as is his later attendance at a conference on MPD that concluded with a poll being ``taken of how many in the audience were treating patients who said they had been ritually abused''--of the 200 or so therapists, ``almost everyone raised his hand.'' And further cases came Mayer's way- -including that of Randall, an anorexic/ bulemic multiple apparently forced to serve a satanic cult by her father, and of Colleen, a professional masochist with perhaps more than 1,000 personalities. Interweaving his account of these cases and the engaging story of his own troubled life--career switches, a difficult divorce--Mayer emphasizes that, for him, the bottom line is not so much whether satanic child abuse exists on a wide scale--he weighs the evidence pro and con without drawing definite conclusions--but how to ``listen to my patients and help them any way I can.'' Once again, Mayer proves a wise and charming guide through some of the darkest corners of the human mind--and a temperate explorer of an ultrasensational phenomenon.