The plot they hatched was as audacious as it was impossible—a 19th-century raid as elaborate and preposterous as any Ocean’s Eleven script. It was driven by two men—a guilt-ridden Irish Catholic nationalist, who’d been convicted and jailed for treason in England before being exiled to America, and a Yankee whaling captain—a Protestant from New Bedford, Massachusetts—with no attachment to the former’s cause, but a firm belief that it was “the right thing to do.” Along with a third man—an Irish secret agent posing as an American millionaire—they devised a plan to sail halfway around the world to Fremantle, Australia, with a heavily armed crew to rescue a half-dozen condemned Irishmen from one of the most remote and impregnable prison fortresses ever built.

Read more of this amazing tale from the Smithsonian.