Based on a novel of the same name by Dava Sobel, Longitude tells the story of John Harrison (Michael Gambon), a humble English carpenter who spent all of his life building clocks in an attempt to win a bold challenge and find a way to accurately determine longitude - an issue that was still open in the early XVIII century, and whose solution would finally make navigation safe and accurate. In 1714, the Longitude Act issued by the English Parliament offered a reward of 20,000 pounds (equivalent to several million euros today) to anyone who could develop an accurate method to determine longitude at sea. Amidst the astronomical methods suggested by astronomers and the weird and unusual solutions put forth by the many amateur inventors allured by the huge reward, Harrison undertook a long study of the mechanisms and raw materials that made clocks accurate and allowed them to withstand taxing navigation conditions. After twenty-five years and three prototypes (H1, H2 and H3) Harrison realized that a solution could only be provided by a small clock and built H4. Despite the opposition of an élite of astronomers and thanks to the support of King George III, the accuracy of H4 finally won him the much sought-after prize when he was over seventy years old. Harrison's story goes hand in hand with that of retired navy officer Rupert Gould (played by an excellent Jeremy Irons), who does not appear in Sobel's novel. The victim of a nervous breakdown during the First World War, Gould later became extremely fond of Harrison's clocks and learnt how to manufacture and repair them in his spare time, until he became obsessed by them as much as Harrison was. Winner of the European Science Fiction Festival, Paris, 2001.