Outside Over There  (English, Paperback, Sendak Maurice)

While Ida is busy playing her wonder horn faceless goblins come in through the bedroom window and kidnap her baby sister. So Ida puts on her mother's yellow rain cloak and sets off on a mystical journey into Outside Over There, to rescue her sister and save her from having to become a nasty goblin's bride. But once she finds the goblin's hiding place she has to employ a very special, clever ftrick before she can carry her sister home to safety.