Lucy's grandmother Poh Poh and her poodle Fluffy arrive for a visit, and Fluffy immediately begins building a doomsday machine that will hypnotize humans and turn them into agents of chaos--can Ember work with the other neighborhood pets to outsmart this evil genius?

It is hard for Chihuahua Ember to decide which is worse: a pack of pugs who announce that they are aliens, or the dog park which is filled with large and overexcited dogs--but he is convinced that he and his animal friends must stop the pugs to save the world (for themselves).

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.

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. "Te presentamos a Chispa, un chihuahua que acaba de ser adoptado por la familia Chin. Chispa no es un perro cualquiera; cree que es un príncipe del mal y quiere gobernar el mundo. Pero sus planes diabólicos se derrumban cuando se entera de que su nuevo vecindario ya...