Late at night in the Zootopia, Little Lightning, the sloth, mysteriously disappeared. Judy, the rabbit policeman, followed the strange claw marks with silver-gray powder, but was intercepted by the smiling fox detective Nick - not only did this fox hide a lot of tricks to tease rabbits, but he also saw at a glance that the claw marks were connected to the "Cloud Realm", a secret city of birds suspended high in the sky. As the eagle owl guards chase and the injured messenger sparrow appears, the two discover the Swan Queen's shocking conspiracy: she uses genetic experiments to modify birds and wants to rule the Animal City through "species isolation." On one side are the strict barriers of the experimental base and the deadly traps of the fog-locked cloud realm, and on the other side are Nick's gentle teasing as he rubs the tips of Judy's ears. This "fox-rabbit partner" not only wants to rescue Little Lightning and resolve the genetic crisis, but also catch each other's sincerity hidden in the adventure during the crisis.
