Fictional story about the Escuadron 201 de Caza (201st Mexican Fighter Squadron), which participated in military campaigns in the Phillipines during WWII. It focuses primarily on two brothers, one who has a promising future as a doctor, who volunteer for this unit after Mexico declares war on Germany after the sinking of Mexican merchants by U-boats. The story also follows another young man, the son of a Spanish immigrant baker. He volunteers to pay what he feels is an unpaid debt to their new adopted country.