Beset by pirates, Knights of Malta, and saboteurs, Captain Matthew Quinton sails to Africa in pursuit of a mountain of gold. When a captured Barbary pirate saves his neck with a tall tale of a fabled mountain of gold, Quinton has his doubts. But King Charles II can't resist the chance to outstrip the Dutch with a limitless source of wealth. With the devious pirate O'Dwyer in tow, Quinton embarks on a voyage beyond the map's edge, still convinced that the mountain is mere legend. But as attempts to sabotage his mission draw closer to the mark, he begins to wonder.