Published in 2009, the book recounts the activities of the British explorer Percy Fawcett who, in 1925, disappeared with his son in the Amazon rainforest while looking for the ancient "Lost City of Z".

As observed by Kirkus Reviews, "Fawcett's exploits in jungles and atop mountains inspired novels such as Arthur Conan Doyle's The Lost World, and his character is the tutelary spirit of the Indiana Jones franchise.

[2] The article documents how Grann, working from Fawcett's long-lost diaries, reconstructed the explorer's last journey, including visiting members of the Kalapalo tribe in the Xingu Indigenous Park region of the state of Mato Grosso, Brazil.

The oral account said that Fawcett and his party had stayed at their village and, despite warnings about "fierce Indians" who occupied that territory, had headed eastward.

[4] Grann reported on excavations by the archeologist Michael Heckenberger at a site in the Amazon Xingu region that might be the long-rumored lost city.

Black Indian earth showed evidence that humans had added supplements to the soil to increase its fertility to support agriculture.

[8] In her review, Kakutani wrote that it: is at once a biography, a detective story and a wonderfully vivid piece of travel writing that combines Bruce Chatwinesque powers of observation with a Waugh-like sense of the absurd.

Mr. Grann treats us to a harrowing reconstruction of Fawcett’s forays into the Amazonian jungle, as well as an evocative rendering of the vanished age of exploration.

Writing for The Wall Street Journal, Simon Winchester said the book was "captivating" but faulted Grann's credulity, especially his imagined observations of the ruins of "Z" and theorizing about what happened to Fawcett.

"[10] Hugh Thomson wrote in The Washington Post that Grann's book "is intelligent and nuanced, as one might expect from a New Yorker staff writer.

"[11] John Hemming dismissed much of the book as hyperbolic in his review for The Times Literary Supplement, concluding, "It is a pity that a writer as good as Grann chose to study this unimportant, disagreeable and ultimately pathetic man.