Secret hideout helps orphan find herself; The Root Cellar, by Janet Lunn. New York: Charles Scribner's Sons. 229 pp. $12. 95. Ages 11 and up.

Rose Larkin doesn't belong to anyone in any place. Her parents died when she was three. She lived with her grandmother in hotels around the world until she was 12, and then her grandmother died in Paris. Rose's relatives in New York don't know what to do with her, until they hit on the idea of sending her to live with her father's only sister, Nan, and her boisterous family. They live in an old house on a rural island off the Canadian coast of Lake Ontario.

Rose has been shuttled about by adults all her life. She never thinks to suggest or protest on her own behalf, but accustomed as she is to great cities and the presence of servants, she feels like an angry outsider among her four rowdy boy cousins, her eccentric aunt, and game-warden uncle. She hates the loneliness of the island and the tumbledown gloom of the as-yet-unrenovated old house that is now home. All Rose wants is to escape - even an orphanage seems better - until she stumbles upon the root cellar and through it into the world of the house's century-old past and into the lives of its former inhabitants.

This award-winning book from Canada has a double appeal. It brings to life an historical period and its formative events, as it deftly depicts one contemporary adolescent's struggle to discover who she is and where she belongs. In her shifts between the world of Aunt Nan's family and the Civil War world of Will Morrissay and Susan Anderson, Rose learns self-reliance; she learns, too, to share herself with others and to balance dependence with responsibility. This is a vivid adventure with bold characters, compelling events and a masterly treatment of issues both social and individual.