A journalist at The New Yorker magazine, Grann discovers the Fawcett mystery while conducting research for a related story. Grann decides to follow Fawcett’s trail, first into the archives and then into the Amazon jungle. The result is a 2005 article in The New Yorker, which Grann expands and then publishes as a book four years later.

Grann’s own story figures prominently in The Lost City of Z. As Fawcett pursues Z, Grann pursues Fawcett, and the two stories run parallel throughout the book. Grann’s research into Fawcett begins at the RGS in London, where Fawcett trained as an explorer more than a century earlier. From there, Grann travels to Wales, where he meets Rolette de Montet-Guerin, Fawcett’s surviving granddaughter. In Fawcett’s logbooks, which Rolette has kept, Grann discovers coordinates for the ill-fated 1925 expedition that differ from coordinates published by Fawcett’s son Brian in the book Exploration Fawcett (1953). Treating this as an important clue, Grann informs his wife Kyra that he intends to go to the Amazon and pick up Fawcett’s trail using those new coordinates.

Grann travels to Sao Paolo, Brazil, and meets James Lynch, a fellow Fawcett-enthusiast who in 1996 launched his own search expedition, which ended when Lynch and 11 of his companions, including his son, James, Jr.