Three children are marooned on an island -- this sort of accident often tends to be overly magnified in juvenile adventure stories. In this case the incident seems to be taken almost casually as an unusual, late-summer idyll made more appealing by the hint of danger. The three are dragged down a storm-swollen river by an uprooted pear tree to a newly formed sand bar. Their isolation lasts for little more than a day, and there's plenty of food on board, so with little to worry about the children go off on their favorite activities, as the youngest makes a miniature garden, her brother draws a map, and the third writes a story. The brief adventure is special to them because it is uniquely theirs -- the island was held together mainly by the branches of the tree, and it disappeared soon after they left. For readers it is all too ephemeral to make much of an impression. By the author of The Riddle of the Figurehead (1963) and others.