In 1573, he joined Guillaume Le Testu, a French buccaneer, in an attack on a richly laden mule train. Drake and his party found that they had captured around 20 tons of silver and gold. They buried much of the treasure, as it was too much for their party to carry. (An account of this may have given rise to subsequent stories of pirates and buried treasure.) Wounded, Le Testu was captured and later beheaded. The small band of adventurers dragged as much gold and silver as they could carry back across some 18 miles of jungle-covered mountains to where they had left the raiding boats. When they got to the coast, the boats were gone. Drake and his men, downhearted, exhausted and hungry, had nowhere to go and the Spanish were not far behind.
At this point Drake rallied his men, buried the treasure on the beach, and built a raft to sail with two volunteers ten miles along the surf-lashed coast to where they had left the flagship. When Drake finally reached its deck, his men were alarmed at his bedraggled appearance. Fearing the worst, they asked him how the raid had gone. Drake could not resist a joke and teased them by looking downhearted. Then he laughed, pulled a necklace of Spanish gold from around his neck and said "Our voyage is made, lads!" By 9 August 1573, he had returned to Plymouth.