One of the author's previous works was entitled How Your Psychic Powers Can Make You Rich, and, practicing what he preaches, St. Clair here conjures up not one but two Linda Blair heroines, both victims of spirit possession. The first to appear in the luckless Illinois town of Watseka is Mary Roff, daughter of the town's most prominent family, victim of ""seizures"" during which she decapitates the cat, screams obscenities, and brandishes a butcher's knife. Mary's parents are frantic and the townsfolk want her committed to the state looney bin. But Mary fools them all: she dies. Interlude. Thirteen years later--we're now in 1877--another family in town, the lowly Vennums, have a daughter named Lurancy who begins foaming at the mouth. . . . But this time a wise and kindly Spiritualist minister hears about the case and intervenes to guide Lurancy through assorted interloper personalities. Eventually Lurancy announces that she's really Mary temporarily domiciled in the Vennum girl's body. Both sets of parents are close to apoplexy but the kindly Spiritualist calms everyone and only a seance or two later--after the evil one who's been inciting the town against Mary-Lurancy burns up in a mysterious fire--Watseka reverts to normal. Long before that you'll be muttering diabolical imprecations of your own against St. Clair, Watseka, and exorcists everywhere.