The Enchanted Castle

Three children spending the summer holidays at school find a hidden garden and in it a sleeping girl who claims to be an enchanted princess. She is really the housekeeper's niece, Mabel, playing a game, but the ring she shows them turns out to be truly magic: it makes its wearer invisible, then does whatever its wearer says it does, and soon the children are dealing with walking statues, people made of old clothes who come alive, and a magic that grows stranger as the summer goes on.

E. Nesbit published the novel in 1907, and its mix of comedy and real wonder influenced many later writers of children's fantasy. Peter Eastman reads it alone, in about seven hours.