Of all the tales of the Knights of the Round Table, the story of Sir Gawain and the Green Knight is surely the most magical.

Here are thrills and enchantment, chivairy and courage, a challenge and a quest.

Its hero is the greatest of all King Arthur's knights, Sir Gawain.

His adversary is the fearsome Green Knight, who rides into Camelot one New Year's Eve with a challenge that strikes dread into Arthur's court.

For Gawain, it is the start of an extraordinary adventure.