"The carousel horses sleep all winter and wake in the spring," two sisters remember their mother saying. Then one gray-skied February twilight, as they make their way home from school, the girls hear strange whinnying noises coming from the carousel. Could it be that the horses are moving . . . clopping their hooves . . . alive? "Rosenberg's atmospheric tale is greatly enhanced by LaMarche's singularly luminous artwork; mist all but lingers on the...