雲霧繚繞的冬日，小男孩跟著學校戶外教學來到帝國大廈頂樓的瞭望台。伸手不見五指的茫茫霧色裡，小男孩和淘氣友善的白雲成為好朋友。白雲背著小男孩來到宛如中央車站的天空之城Sector 7。原來Sector 7是個雲霧派遣中心，掌管各種雲霧的設計與任務派遣。可是活潑的雲霧們早就厭倦了管理人員一成不變的藍圖，而小男孩有辦法解決這個令雲苦惱的問題嗎？
Sector 7是凱迪克獎常勝軍David Wiesner繼Tuesday後的另一得獎作品。延續一貫的無字風格，Wiesner以一幅幅細緻的水彩勾勒出小朋友創意十足的想像空間，與單調刻板的成人世界相映成趣。而全書沒有文字框架的束縛，更烘托出小朋友想像力豐富、創造力十足的特質。
Only the person who gave us Tuesday could have devised this fantastic tale, which begins with a school trip to the Empire State Building. There a boy makes friends with a mischievous little cloud, who whisks him away to the Cloud Dispatch Center for Sector 7 (the region that includes New York City). The clouds are bored with their everyday shapes, so the boy obligingly starts to sketch some new ones. . . . The wordless yet eloquent account of this unparalleled adventure is a funny, touching story about art, friendship, and the weather, as well as a visual tour de force.
David Wiesner's interest in visual storytelling dates back to high school days when he made silent movies and drew wordless comic books. Born and raised in Bridgewater, New Jersey, he graduated from the Rhode Island School of Design with a BFA in Illustration. While a student, he created a painting nine feet long, which he now recognizes as the genesis of Free Fall, his first book of his own authorship, for which he was awarded a Caldecott Honor Medal in 1989. David won his first Caldecott Medal in 1992 for Tuesday, and he has gone on to win twice more: in 2002 for The Three Pigs and in 2007 for Flotsam. He is only the second person in the award's history to win the Caldecott Medal three times. David and his wife, Kim Kahng, and their two children live near Philadelphia, where he devotes full time to illustration and she pursues her career as a surgeon.