Again, as in The Haunting (1982), New Zealand writer Mahy proves that all-out supernatural stories can still be written with intelligence, humor, and a fearful intensity that never descends into pretentious murk or lurid sensationalism. Laura, 14, living with divorced Mum (a bookstore manager) and little brother Jacko in a small New Zealand town, is a "sensitive." She gets "warnings" when big disturbances--like her parents' divorce--are imminent. She has the ability to take one look at older schoolmate Sorensen Carlisle and know that he's a witch. And when an old junk-store owner named Carmody Braque playfully stamps Jacko's hand with a smiling replica of Braque's own face, it's Laura who soon realizes that something ghastly has happened: "the stamp was part of him now, more than a tattoo--a sort of parasite picture tunneling its way deeper and deeper, feeding itself as it went." Jacko falls ill, then becomes seriously, mysteriously sick, wasting away, comatose, in a hospital bed. Laura's distraught mother, now growing closer to a librariansuitor, can't even listen to her daughter's ideas about the supernatural causes of Jacko's decline. So Laura desperately turns for help to "Sorry" Carlisle, who lives in a forbidding ancestral manse with his mother and grandmother--good witches who tried (in vain) to give Sorry a normal life away from magic. At first the Carlisles are cautious, distant, slow to admit their witchly powers; Sorry, deeply ambivalent about witch-hood, is sarcastic, sexually teasing. But eventually they agree to guide Laura in her battle for Jacko's life against Carmody Braque, a demon who must feed on human souls and bodies. The first step? Laura must make the "changeover" into witch-hood--something her psychic sensibility makes possible. (The visionary ritual involved is a perfect mix of the chilling and the comic, with Laura taking pot-shots at the poor literary quality of Sorry's chants.) Then, with moral support from Sorry, Laura must have a one-on-one confrontation with demon Braque, hiding her new witch-hood behind dark glasses and stamping his hand with a sign of her power. And finally, after Braque's Oz-style annihilation ("he continued to change back through the centuries of stolen life until his clothes collapsed around what at first appeared to be a rotting, heaving mass"), Laura can celebrate Jacko's recovery--and her own recovery from "a secret illness no one had ever completely recognized or been able to cure": the post-divorce hatred of her father, the jealousy of her mother's new boyfriend. Mahy thus invests the occult evils here with a metaphorical, psychological undertow; at the same time, however, while filling out all the characters (including the witches) with textured charm, she never stints on thoroughgoing creeps and scares. In sum: the best supernatural YA fiction around, with Stephen King power and Mahy's own class and polish.