On September 26, 1580, Francis Drake sailed his ship, the Golden Hinde, into Plymouth Harbor on the southwest coast of England. He had long been given up for lost, and rumors quickly circulated about where he had been on his three-year round-the-world voyage, and about the plunder he had brought home to fill Queen Elizabeth's treasury. However, a veil of secrecy was immediately imposed on the expedition: Drake's journals and charts were impounded,...