It is 1702, and in the lawless Caribbean Sea, young Matthew Loftus captains his ship, the Cornelius, and vows to engage in honest trade rather than piracy and plunder. But his crew lusts after the spoils that their fast, well-armed vessel could win, and discontent begins to rumble. Meanwhile, Loftus is pursued by the English Navy on a false charge of mutiny. Matthew must evade the King's ships and escape the attention of ruthless privateers. His only chance of pardon rests with a secret almanac that promises that elusive prize-to solve the Longitude Problem. But is the almanac what it seems? Through wild gales and fierce sea battles, uprisings and reversals of fortune, Matthew sails his beloved schooner towards victory.