The author traveled from the USA to Mexico. A famous author, he could access places you or I could not: Local writers gave him letters of introduction; but nobody knew what he looked like,* so he could go places looking like "just another old gringo."
He traveled along the USA-Mexico border, talking to migrant folks. In Mexico's interior, he visited a sort of sanctuary where migrants from the south and beyond Mexico could rest. And as he visited not-migrant Mexicans, he asked if they'd ever traveled to the USA to work (and a surprising-to-me fraction of them had). America's then-president was bleating that everyone crossing that border were thieves and rapists. But that then-president was a racist asshole grabbing at votes from America's most gullible racist assholes. This book gives a clearer picture of border-crossers: a few thieves and rapists; many upstanding people seeking work to send money home to their families; some people fleeing places taken over by bandits; some people fleeing countries taken over by USA-sponsored death squad bandits. Folks from the same town tend to migrate to the same far-away place, using connections established by previous migrants; folks from some towns might not migrate to the USA, but instead to Mexico City, which might seem about as foreign, depending.
But this book's author didn't just learn about migrant folks. He's an author. He talked to and about Mexican authors and artists. He taught a writing seminar in Mexico City and this gave him an "in" for meeting other artist/academic types around the country. So he did that. (I didn't pay so much attention to these parts of the book. The author really really doesn't like magical realism; I don't like it so much either, but don't have a professional obligation to read it and thus wasn't so interested to read a long explanation of why I needn't like it…) The author was more impressed with Francisco Toledo an artist who boosted his community.
Mexico's federal government is a mess that helps nobody. Whenever the author drove in Mexico City, some corrupt cop would pull him over to shake him down for a bribe. (When driving around the rest of the country, he encountered another kind of driving hazard: anti-government protests that blocked the road. But by the time he encountered those, he'd seen enough government corruption to know those protests were warranted.) Eventually, he made his way down to Chiapas in the south of Mexico. This area was (and is) under the control of the Zapatistas, not the federal government. This area is having a rough time; but its pretty clear that their government is, while not perfect, doing a much much better job than the Mexican feds.
Anyhow, it was an interesting read. Check it out.
*This is not 100% true; one person recognized him.