Everyone knows that the stork delivers babies, but where do the storks get the babies from? The answer lies up in the stratosphere, where cloud people sculpt babies from clouds and bring them to life. Gus, a lonely and insecure grey cloud, is a master at creating "dangerous" babies. Gus's beloved creations are works of art, but more than a handful for his loyal delivery stork partner, Peck. As Gus's creations become more and more rambunctious, Peck's job gets harder and harder.