It turns out there are many children left behind by fathers and, increasingly, by mothers. (Driven by an inability to feed their children they usually head north intending to stay only a year or two - but end up staying much longer, not so much dazzled by El Norte as exploited by it and unwilling to return with nothing to show for their efforts.) Each year tens of thousands of children make the dangerous journey north, too, in search of the mothers they fear have abandoned them.
Nazario retraced the journey of a teenaged boy from Honduras whom she met in Nueva Laredo, just south of the US border in Mexico; by that time he'd already tried eight times to make it to the US to see his mother, Lourdes, whom he had not seen since he was five. Over the next few years Nazario met and interviewed Enrique's family in Honduras and a remarkable number of the people he met on his way - and also traveled as he did, on the top of freight trains (though she was able to ensure there were police on board in case one of the gangs of thieves who beat and rob many migrants, including Enrique, tried to attack her), hitchhiking, etc.
At the same time she kept in touch with Enrique and Lourdes, and chronicles their difficult reunion in North Carolina - after initial joy and disbelief came resentments and shouting-matches; it took a few years for them to find their way to something like an affectionate relationship. But even as all this was happening, Enrique's girlfriend in Honduras bore his child, raising the same questions all over again. He finds a way to have her smuggled up - in two years they'll have earned enough money to return to Honduras and their little girl. They hope. Perhaps they'll have better luck than Lourdes. But in the meantime, young Jasmin is, like Enrique before her, being passed from hand to hand.
The resulting book is powerful and disturbing, and raises deep questions about immigration to the US, its causes and consequences. Nazario's conclusion is that this particular stream of illegals can only be stopped at the source - nobody leaves her children willingly. Meanwhile, the toll taken on children by absent parents is huge, and seems to have repercussions for years.
Along his way through southern Mexico, Enrique is robbed and terrorized by gangsters and policemen in Chiapas, but when he finally makes it through to Oaxaca and Veracruz is amazed to find that people along the rails come meet the trains and throw the migrants food, drink and clothing. Nazario met some of the food throwers (as she calls them) and found them to be poor but energized by the need they could meet. A visionary priest was one inspiration; another was the memory of sons and brothers who had themselves headed north, few to return and some of whom had never been heard of again
The image above seems a vision of goodness to me.