Ten years have passed since the cat-dog truce in the second film. The cats and dogs have jointly invented a monitoring system to maintain peace and resolve conflicts. However, when a tech-savvy parrot appears, uses his "hacking" skills to invade and use frequencies that only cats and dogs can hear to control them, cat-dog wars break out again around the world! So, a group of inexperienced novice cat and dog agents have to use the most primitive way to restore peace.