Makina lives in a small Mexican town with her mother Cora. She is in charge of the village switchboard, relaying messages from people in three different languages. Because of her strong sense of confidentiality, she is trusted and respected by the entire village community, including the gangster bosses who reign there.
One day, Cora asks Makina to deliver a note to her son, who went across the border to the U.S. to claim some disputed land. The note simply asks Makina’s brother to come home. Following her mother’s advice, Makina meets with Mr. Double-U and Mr. Aitch, two gangster bosses who offer help. In return, Makina must deliver a mysterious package to a contact in the United States.
On the bus to a border town, Makina encounters a young man who tries to grope her. In self-defense, Makina almost breaks his finger and is able to stop the harassment.
After the bus ride, a man named Chucho awaits her and accompanies her on her journey over the border. He saves her from drowning in the Rio Grande and fends off a ranger who tries to arrest them.
Having arrived in the U.S., Makina first hands over the package to Mr. P in a stadium. After that, she continues her search for her brother but finds the man from the bus working in a restaurant. The restaurant owner remembers having seen her brother and gives her the address of the place he went to.
However, instead of her brother, she meets a black man who tells her that the family who used to own the house left their oldest son, a soldier, behind.
Makina finally finds her brother at the army barracks. He recounts that he was taken in by a wealthy American family, but when their son was supposed to join the army and go to war, they begged him to take his place instead and offered him some monetary reward. After a few months at war, her brother tried to claim the reward but since the family did not expect him to come back alive, they are unable to pay him in full. Since then he has been staying in the army under an assumed identity. Having no clear goals or ambitions, he rejects Cora’s request to come home.
After leaving her brother, Makina encounters a policeman who tries to arrest her and a couple of other illegal immigrants. However, when she exposes his racism in his own language, he leaves in bewilderment.
Walking away from this incident, she meets Chucho again, who brings her to a secret place where she receives a new identity and indicates that she wants to stay in the United States.
