"El Grillo" has just been released from prison. The first thing he does is go to the "headquarters" of his old gang, captained by "El Señorito". In the band "El Señorito" business does not go well. It is increasingly difficult to live on the theft of wallets only, and Don Rafael "El Cajero" -administrator of society- suggests a change of method in his work. They decide that the best way to learn how to hit bigger blows is to send one of them to North America. Thus, "El Señorito" begins an accelerated English course in 20 days, falling in love with the teacher, to whom he lies about his work and projects, and finally leaves for Chicago.