Cirque du Soleil is less a traditional “circus” and more high-level performance art. There are wonders and tricks to amaze you, sure—but they are elegant instead of gaudy, graceful instead of brash. A festival of imagination and physical feats. And if the traditional circus is thought of as “kid stuff,” Cirque du Soleil is aimed squarely at adults. Aerial silks, contortionists, fire jugglers. That is precisely why initially, the theme for Toruk: The First Flight, based on James Cameron’s Avatar, was puzzling to me....