Academy Award winner Jeremy Irons stars in this sweeping adaption of Dava Sobel's best-selling book of high seas adventure and political intrigue. Determined to stop shipping losses on the oceans of the 18th century, Britain's Parliament offers a fabulous cash award to anyone who can devise a way to determine longitute at sea. Convinced he can solve the problem that has defeated England's best minds, rural clock maker John Harrison (Michael Gambon) begins an obsessive, 40-year struggle to claim the Longitude prize with his ingenious marine clock. 200 years later, naval officer Rupert Gould (Jeremy Irons) stumbles across Harrison's forgotten chronometers and devotes himself to restoring these long-neglected mechanical masterpieces.