At the age of five, Enrique watches his mother, Lourdes, leave their doorstep in Honduras. He does not know that she will not return. Lourdes is heading to the United States in search of work so that she can send money home to her two children, Enrique and Belky. Her experience in America is not easy; she becomes pregnant and works many different jobs. She wires money back home, but feels guilty and sad at the thought that her children are growing up without her. Meanwhile, Enrique struggles through his childhood and wishes for his mother's return. After many false promises, he begins to realize that she may never come home. He becomes lonely and angry, and turns to drugs when he becomes an adolescent. He moves from house to house under the care of different family members. When he is seventeen, he knows that he cannot continue his life in Honduras without the love of his mother. He sets out to find his mother in the United States, determined to make the difficult journey through Guatemala, up Mexico, and across the river. With hardly any money and few belongings, he leaves his hometown of Tegucigalpa and travels north.
Enrique must cross thirteen of Mexico's thirty-one states and traverse over 12,000 miles to reach his mother. He is one of many children who make a similar journey in search of a parent. The journey is extremely dangerous—he must face the depredations of bandits, gangsters, immigration officers, and corrupt police. Every region is different, and he must learn what to look out for and guard against through multiple trials. He attempts the journey from Honduras seven times. Much of the trip is made atop freight trains, where the chances of getting severely wounded and even dying are high. He survives the trip because of his perseverance, luck, drive, and above all, with the help of others. On his way, he meets fellow migrants with whom he shares stories and common experiences. In spite of the harsh circumstances and the ruthless people who target migrants, Enrique also encounters generous, kind, and compassionate people who offer their help at the risk of their own punishment. Although he makes much of the journey alone, crossing the river is too risky on his own. After getting in touch with his mother, he is able to secure a smuggler, his protector El Tiríndaro, to help him cross the border. Finally, on the eighth journey, after an arduous and long trip, he finds himself in the hands of his mother.
Their reunion, at first, is happy. Lourdes has established a good life in North Carolina with her boyfriend and daughter, Diana. Enrique is glad to be with his mother, but soon the complicated feelings of abandonment and anger come out. He and his mother begin to argue, and their relationship becomes tense. Back home in Honduras, Enrique's girlfriend, Maria Isabel, gives birth to their daughter, Jasmin. Enrique longs to bring his family to the United States, but continues to struggle with drug addiction and emotional problems. He sends money back to Maria Isabel as often as he can, but their relationship becomes strained. Maria Isabel receives criticism from Enrique's family members about how she is raising Jasmin and spending Enrique's money. Maria Isabel grows closer to Jasmin and has trouble deciding what will be best for her child. Finally, she decides to go to the United States to join Enrique. If she leaves now, the chances that her daughter will be able to come to America and grow up with both her parents will be higher. The book ends much in the same way that it begins: with a mother leaving behind her young child, unable to say goodbye.