At the center of it stood Ronald Richter, an Austrian-born scientist who had drifted into Argentina in 1948 among a wave of German engineers Perón recruited after the war. He arrived under a false name, Dr. Pedro Matthies, and was introduced to the president by the famous aircraft designer Kurt Tank. Richter pitched a fusion device he called the Thermotron, promising unlimited power, scientific glory, and purely peaceful intent. Perón was dazzled. 'In half an hour he explained to me all the secrets of nuclear physics,' the president later told reporters, 'and he did it so well that now I have a pretty good idea of the subject.' Perón handed him what amounted to a blank cheque. Argentina's own physicists, meanwhile, smelled something wrong from the start and quietly kept their distance.

Richter demanded secrecy, claiming saboteurs and spies surrounded him. So Perón chose Huemul Island, a speck of land in Lake Nahuel Huapi, where the laboratories could be sealed off from the world. Construction in 1950 grew so frantic it caused nationwide shortages of brick and cement. What happened inside the walls verged on the absurd. When the first reactor was finished, Richter realized he had built a twelve-meter concrete cylinder with no way to get inside its four-meter-thick walls; then he declared a crack had ruined it and had the whole thing torn down. He ordered a deep shaft drilled into hard rock, changed his mind, and had it filled back in with concrete. Money and materials vanished into a project that was, increasingly, theater.

On February 16, 1951, Richter declared he had achieved fusion. A technician immediately objected, suggesting the reading came from a photographic plate that had simply been tilted by accident during setup. Richter refused to repeat the experiment. Perón, sensing political advantage on the eve of a summit of American leaders, announced the triumph anyway. The reaction abroad was electric and skeptical in equal measure. The physicist George Gamow judged it '95 percent pure propaganda.' Edward Teller put it more memorably: 'Reading one line one has to think he's a genius. Reading the next line, one realizes he's crazy.' From Vienna, the physicist Hans Thirring estimated the odds at 99 to 1 that the whole thing existed only in the imagination of a crank or a fraud.

Here lies the strange twist. The fraud was empty, but the panic it triggered was real, and it jolted the world's physicists into action. At Princeton, the astrophysicist Lyman Spitzer read about Huemul in the newspaper before a ski trip, dismissed Richter's method as impossible, and began puzzling over how a plasma might actually be confined. The result was the stellarator, the magnetic-confinement reactor that founded American fusion research. Spitzer himself used the publicity around Richter's claim to win his first government funding. In Britain and the Soviet Union, fusion programs that had been languishing for lack of interest suddenly found money flowing. A lie told on a Patagonian island helped kick-start a global scientific race that continues to this day.

By 1952 Perón could no longer ignore the doubts. He sent a small committee to the island, and among them was a young Argentine physicist named José Antonio Balseiro, called home in haste from his studies in England. Balseiro's report was devastating and precise: fusion would require temperatures around 40 million kelvin, while Richter's electric arc reached perhaps 100,000 at most. When a military team finally occupied the site in November 1952, they found instruments that were not even connected to anything. Argentines came to call the affair the Huele a mula, the con that smells like a mule. Richter was eventually arrested for fraud, drifted abroad as far as Libya, and died in Argentina in 1991. But Balseiro turned the wreckage into something lasting. He proposed using the island's expensive equipment to found a real physics institute on the mainland, and from the ashes of the hoax rose one of South America's finest scientific schools, which today bears his name.