From two newcomers to children's books, a dreamy glimpse of the way in which children make use of the world around them in imaginative play and wonder. Twins Jonathan and Rachel take the same walk around the land surrounding their farm house, but they see things quite differently. In a perfect illustration that defines them and the day, Jonathan is shown in t-shirt, shorts, and sneakers, peering through thick-lensed glasses and pointing skyward, while Rachel, her back to him, wears a picturesque frock, and is absorbed in collecting wildflowers. In the leaves of a huge willow tree, Jonathan sees a dragon looming, while Rachel looks at sheltering limbs and carpet of leaves. Rachel's quarreling blue jays and noisy squirrels are Jonathan's aggressive forest trolls, and so on. At the page-turning cliffhangers, readers will want to shout along with Jonathan--story hours could get noisy. The summer setting is joyfully delineated in Portwood's watercolors, which capture the fluid movements of the children and gracefully depict realistic and fantastic scenes. About half the size of most contemporary picture books, this one proves how much can be done with small, tidy dimensions.