One housing development after another was destroying the beautiful woodlands around the City, spoiling the beauty of natural surroundings and leaving animals homeless. One day, the animals animals of every description, led by a mysterious cat – actually rebelled and launched an attack upon Mankind. While puzzled authorities pinched themselves to see if they were really awake and groped for ways to meet the strange attack, Astro Boy investigated the source of the rebellion and discovered it to be none other than a human being-one Professor Greenthumb, a dedicated naturalist and friend of homeless animals. The professor had learned how to communicate with animals. It was he who had planned and organized the uprising. Making peace with him and his horde, and at the same time saving the woodlands from destruction, was to become one of Astro Boy’s most unusual and vexing assignments.