"When I was in school, I spent all this time studying international relations, immigration, border security. I was always reading about policy and economics, looking at all these complex academic ways of addressing this big unsolvable problem. When I made the decision to apply for this job, I had the idea that I'd see things in the patrol that would somehow unlock the border for me, you know? I thought I'd come up with all sorts of answers. And then working here, you see so much, you have all these experiences. But I don't know how to put it into context, I don't know where I fit in it all. I've got more questions than ever before."

This quote from the book is part of a conversation Francisco Cantú, the author of this memoir, had with one of his fellow Border Patrol agents. After graduating with a B.A. in International Relations, Cantú decided to experience the realities of law enforcement at the Mexico-United States border for himself - much to the dismay of his concerned mother, a former Arizona park ranger: "You grew up near the border, living with me in the deserts and national parks. The border is in our blood for Christ's sake - your great-grandparents brought my father across the border from Mexico when he was just a little boy."

As a grandson of immigrants, Cantú was now directly confronted with the plight of migrants seeking a better life, many of them dying during their dangerous passage through the desert, the cartels, trafficking drugs and people, the local inhabitants and farmers who are fearing both cartel violence and raids by hungry and desperate migrants, and the psychological toll the dangerous work of patrolling the "unnatural divide" takes on his colleagues and him. Faced with a multitude of dangerous and bloody stories, the "big unsolvable problem" of the border starts to weigh Cantú down. Instead of making peace with the wolf, as his patron saint Francis of Assisi (after whom his mother named him) did, a wolf starts to haunt Cantú's dreams: "I dreamed of a cave littered with body parts, a landscape devoid of color and light. I saw a wolf circling in the darkness and felt its paws heavy on my chest, its breath hot on my face. I awoke (...). Then, for several minutes, I stared into the mirror trying to recognize myself."

What makes this text so strong is that Cantú manages to give a nuanced account, presenting the factual and the emotional without getting carried away on neither side. He puts all of his knowledge to work in order to make sense of the border as a concept and as an actual phenomenon: His family background, the historical, sociological and psychological research on the impact of the border and the violence that occurs there, as well as his experiences as a border patrol agent and as a friend of a deported Mexican. On the level of language, factual accounts, stories, studies, and highly poetic bits are intertwined, and the change of style and tone add to the depiction of the border as a contradictory and multi-layered reality that can be encircled, but never fully grasped (Cantú left the Border Patrol and got an MFA in Creative Writing).

The title "The Line Becomes River" hints at the fact that the Rio Grande forms part of the Mexico-United States border, the fluidity of the water somehow mocking the character of the border as a fixed barrier: "As I swam toward a bend in the canyon, the river became increasingly shallow. In a patch of sunlight, two longnose gars, relics of the Paleozoic era, hovered in the silted water. I stood to walk along the adjacent shorelines, crossing the river time and again as each bank came to an end, until finally, for one brief moment, I forgot in which country I stood. All around me the landscape trembled and breathed as one."

Francisco Cantú already won the 2017 Whiting Award for Nonfiction for this book, and it is pretty easy to see why: Cantú does not only discuss a very current topic and shatters disgusting racist stereotypes, he also does not fall into the trap to turn his memoir into a pamphlet against the madman in the White House (who is not mentioned with one syllable throughout the whole text). It is the factuality and nuance of the book that make this account credible and moving.