Falcon begins in the loins of Uther Pendragon, besotted in an instant with the beauty of Igrayne, wife of the Duke of Corwell. Merlin helps him have his way. Thus, rape and murder become the adulterous origin of Arthur. Morgan, daughter of Igrayne and the Duke, a child of unusual intelligence and curiosity, informed of all this and seeing what evil magic has done to both mother and father, uses the seduction of Merlin and the stay at a convent to make sorcery her own tool of revenge.
While she settles in in the north, growing in enmity and in sorcery, Arthur grows up, draws the sword from the stone, and, largely through a murderous military campaign against the kings of the north, becomes king. He invites young knights to join a chivalric fellowship which he intends to guard women and holy Church. Gawain, with his brothers, comes to Camelot, becomes a knight, taking on and believing in the all-night ceremony's virtue. When, on New Year's Eve, Arthur and the vaunted knights of the Round Table are visited by the intimidating Green Knight, Gawain steps up to rescue Arthur, then rues his rash courage as he begins to see in the reluctance of the other knights a look-the-other-way fly in knighthood's ointment. His doubt grows through the year he must wait before, having bravely given his word, he must present his head to the Green Knight, a year during which Morgan needles Arthur from afar with falcon magic: the shock of the Green Knight's face during Easter Mass, the scary songs of an itinerant troubadour, a horrific conclusion to the Pentecost tournament.
The year of waiting over, Gawain sets out on his obligatory journey. On the way, he has encounters that add to his uncertainty about the whole enterprise. He meets a victim of Arthur's wars, a Welsh widow he stumbles upon. Then he encounters a hermit monk who billets him for the night and gives him food for thought, before mysteriously disappearing. He eventually reaches the castle of Sir Bertilek where he learns he's surprisingly close to the Green Knight's "chapel;" also, where he unexpectedly encounters Morgan le Fay who has a message for him. He survives a determined seduction effort by Lady Bertilek, commits a major knightly faux pas, and finally finds his way to the Chapel of the Green Knight on time.
Falcon is true to the original story in its presentation of the final encounter between Sir Gawain and the Green Knight, though not entirely. All happens just the same, but with a new meaning.
