Throughout the book Cantú gravitates toward, and finds meaning in, the desert landscape. This is partly due to growing up as the son of a park ranger in a desert national park, but it is also due to Cantú’s Mexican American heritage. The desert becomes a character in and of itself, one that Cantú is both attracted to and repulsed by during his time in the Border Patrol and beyond. As a place, the desert is described as a series of contradictions: It is bad and beautiful, alien and knowable, brutal and entrancing. Cantú uses historical documents, personal narratives, political and sociological texts, and literary works by Mexican and Mexican American writers to better understand the Southwestern United States as a place and the desert as a larger symbol for the US-Mexico border.

Cantú engages with the desert and its terrain and wildlife to showcase how life can flourish even in difficult conditions. The desert becomes a metaphor for the kinds of tensions he explores throughout the book, particularly how human beings are willing to endure impossible physical conditions and distances for a chance at safety and a better life. José amplifies this in his section at the end of Part 3, in which he makes clear he will stop at nothing to cross the border and reunite with his wife and children.