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.