For Ember, a rescue Chihuahua and the newest pet in the Chin family, the first step in fulfilling his destiny to rule the world is to defeat the evil neighborhood squirrel, Masher.
Despite being warned that kittens are monsters, Ember the Chihuahua (who still aims for world domination) agrees to babysit a family of kittens for three days after the mother cat offers him an army in return.