Paco's donkey, Terco, seems to the little Mexican the most wonderful animal and the most desirable vehicle south of the Rio Grande. But to the other children, Terco's somewhat rambunctious behavior does not recommend him as a playmate and Paco's father is convinced that an automobile would make a far more efficient means of transportation than the erratic burro. So it is decided that Terco will be replaced by an automobile, and it is a forlorn Paco who sets off with his pet to the fiesta where Terco will be sold. On the way, however, Paco's father's new car stops and it is only because of the burro that he is able to continue his journey. Terco is redeemed and it is a happy little paisan who nuzzles his ""good-for-nothing burro.