In a little airport near Santiago, Chile, live three airplanes, a papa plane, which carried mail over the Andes between Chile and Argentina, a mama plane, and a baby plane, . spends his days at flight school, hoping to grow up to be like his father. One day, his father has a cold in his cylinder head, so gets the call to cross the Andes, past the forbidding peak of Aconcagua, to pick up and bring back the mail from Mendoza. takes off, and the trip to Argentina goes well. Then, gets cocky, and the return trip goes badly. Will Aconcagua claim another victim? And what of the mail, does it get through?