Sally wants to fly her kite but can't seem to work out the timing to get the wind right - after all, you can't see wind. The Cat takes them to Windnasium where they learn to "see" wind in all kinds of ways. When Nick's favorite flyer gets stuck in the tree, Nick wishes he could jump really high and retrieve it, but gravity holds him down. Cat takes them to Gravity Drop where they discover what happens when there's more or less gravity. And Nick figures out how to use gravity to get his plane back.