Percy Fawcett was a British explorer in the 1920s. He was no stranger to exploration; he had led numerous trips to the Amazon before and was convinced that there existed a great, ancient city. Fawcett believed that this metropolis was a still-active kingdom comparable to the likes of the Incan Machu Picchu or the Aztec Tenochtitlan. Despite the lack of evidence that such a civilization survived, the explorer was dead-set on discovering it – and he named the city "Z."

On April 20, 1925, Percy, along with his son, Jack, and his son’s best friend, Raleigh Rimell, arrived in Rio de Janeiro, Brazil. Brazil was vastly unchartered at the time, and even today, much of the Amazon remains unexplored by the outside world. Fawcett entered the jungle with the help of native guides. They led him to his furthest charted point, ominously called “Dead Horse Camp” because on a previous trip he had shot his overly exhausted equine. The group moved along as the guides turned back, armed with a letter to Fawcett’s wife reporting that they were healthy and making good progress. They continued into the wild jungle with a pace set at ten miles a day. The crew suffered swarms of mosquitos and dense vegetation at every turn. One can imagine the stifling humidity of the summer, the physical fatigue of trekking through a rainforest, and the constant fear of becoming prey to a jaguar. But that’s it – one can only imagine. Percy Fawcett was never heard from again. He had disappeared.

The letter to his wife, written on May 29, 1925, was the last correspondence between Percy and the public. After two years of no contact, it was clear that something had gone wrong. The people of Britain had eagerly hoped for their famous explorer’s return but now speculated about his death. Did he ever reach the city of Z? Was he captured or killed by hostile tribes? Was he eaten by a jaguar, or had he fallen ill to a new disease? Conspiracy theories spread like the plague. Some believed he had joined a tribe or even found the city Z and became its king.

In 1928, the Royal Geographical Society sent George Dyott to retrace Fawcett’s path. He found no clues or remains. He concluded they had died or simply vanished. In 2005, journalist David Grann followed the same trail as Dyott and met with the Kalapalos, a native tribe who told of a legend, a story passed down from generation to generation, about encountering a white man. They had warned him to turn back or risk entering the territory of a very hostile tribe. He had not listened. Grann assumed that this man must have been Percy Fawcett.

Most conclude that the explorer and his group had been killed. Yet, despite years of searching, no one has found any trace of the three men or their supplies. While Percy’s death seems logical, the mystery of Z endures. Is there really an undiscovered city in the heart of the Amazon?