In 1526, several ships of a Spanish expedition entered the Pacific from the Straits of Magellan. One of them, the San Lesmes, was never seen again. Four centuries later, in 1929, four iron cannons were found on the reef of Amanu atoll, French Polynesia. The find created little interest until 1975, when Robert Langdon argued that the cannons were from the San Lesmes, the crew had survived and intermarried and that vital aspects of the wider development of Pacific island communities needed to be reassessed. Now, in Kon-Tiki Revisited, Langdon makes an outstanding contribution to our knowledge of the complexity of Polynesian origins.