Over-indulgently heralded in its opening titles as "A Cinematic Adaptation of the Chivalric Romance Sir Gawain and the Green Knight by Anonymous," writer-director David Lowery's latest film sees Sir Gawain of Arthurian legend portrayed by Dev Patel as a brash and intemperate youth to whom we are introduced in a brothel, cavorting with an unnamed prostitute played by Alicia Vikander. This, in stark contrast to the guileless exemplar of courtly virtue presented in the 14-century poem on which the movie is based. Our story begins on Christmas Day. Attending a celebratory feast at the Round Table, Gawain is summoned to the side of his aunt and uncle, Queen Guinevere (Kate Dickie) and King Arthur (Sean Harris), who kindly chastise him for having no tales to tell of his own adventures, what with medieval courts being quite obsessed with tales of adventure, tests of mettle and virtue, quests for honor and all that. Opportunistically, Gawain's mother (Sarita Choudhury) - who...