Crew draws from actual 19th-century cases for this chilling but clumsily told tale of a murderous foster mother. Forced for as long as she can remember to care for a changing cast of small children while vile-tempered, secretive Mama Pratchett idles about or goes off on mysterious errands, only gradually does young Sarah come to realize that something is amiss. Not only do they abruptly pick up and move every few months, but time and again a new baby arrives just after another has suddenly disappeared (hospitalized, Mama Pratchett claims) or died. Until a final revelation clears things up, readers will wonder how Sarah could be telling her tale in such a formal, cultured voice, as she has never attended school; even then, how she can read, or know what she does know of the outside world, is never explained. Considering her cloistered circumstances, Sarah’s reluctance to blow the whistle on Mama Pratchett, even after helping her bury a tiny corpse in the back garden, is more believable. But Crew further damages the tale’s credibility by giving Sarah a ghostly vision of her real mother, an aristocrat who ultimately steps up in the flesh to reclaim her after Mama Pratchett is sent off to be hanged. The story may be every bit as grim as the cover illustration promises, but loose ends and a fairy-tale conclusion spoil its effectiveness. (Fiction. 11-13)