Off the Map
The first thing we see is a map, "wet and crumpled, the lines I had traced to highlight my route now faded" (Preface.1). We can try to mentally draw a little dotted line on it, like when Indiana Jones trots about the globe, but it's no good. David Grann is lost.
There are other maps, too. A young Fawcett possesses a map of Ceylon that he hopes will lead to a mystical place called Galla-pita-Galla. It doesn't. Grann studies Fawcett's journals and letters, turning them into a metaphorical road map to his location. Grann says, "I knew it would take me days, if not weeks, to go through everything, and yet I felt delight. Here was a road map to Fawcett's life as well as to his death" (5.24). And before traveling to the Amazon, Grann uses Google Earth, marveling that "What was once blank space on the map was now visible in an instant" (11.2).
This is all well and good, but none of these maps lead anywhere—a fact Grann realizes in the book's final chapter, when he looks at the same map he mentioned in the preface. "The Z in the middle suddenly seemed ludicrous, and I began to curse Fawcett" (25.32).
When in the Amazon, maps are useless. The only place they will lead you is to certain death.