Rosemary and her family have high hopes for the lovely old country house: it's generously equipped with a study for Dad, a practice room for Mom, who teaches dance, and space for brother Nicky's fossil collections. Still, Rosemary reluctantly realizes, something is trying to make them unwelcome: her bike and other treasures disappear, the weather is unseasonably cold, and there are mysterious manifestations like a sinister cat and a plague of toads. Meanwhile, Rosemary becomes friends with a comfortingly sensible neighbor boy, Ernie; together they investigate the house's link with Mathilda, an ancient crone seen at a shack in the nearby woods. Vignettes from Mathilda's life, alternating with Rosemary's experiences, reveal that she is the witchy remnant of an unloved child, still yearning for affection and for her former home as she faces a decisive choice on her 150th birthday. The author adroitly weaves the dynamics of this engaging family into her pleasantly spooky tale: Rosemary, who sees herself as the only family member without a special calling, is actually a lover of words who is often tongue-tied because Dad, in his enthusiasm for categorizing everything, tends to ``go on at her.'' At the same time, Turner thoughtfully explores the idea of home and how it can be shared. In the end, Rosemary's willingness to give Mathilda her best-loved possession sets the woeful creature free —and also frees the house and town of her malevolent presence. A skillfully written, entertaining story. (Fiction. 10-14)