“One. Year. Hence.” It’s Christmas at Camelot in the opening act of David Lowery’s Arthurian fantasy when the severed head of the Green Knight (Ralph Ineson) utters this ominous tagline, heralding two of the film’s most persistent structural elements: the cycles of nature and the ineffable logic of fairy tales. A double prologue signals the mysticism and earthiness we expect of medieval fantasy: a prophetic voice, a king with orb and sceptre, an icon set alight; a hasty departure from a barnyard in winter. The barnyard abuts a brothel, where the king’s nephew, Gawain (Dev Patel), is awakened by his lover, Essel (Alicia Vikander). “Christ is born,” she greets him; “Christ is born indeed,” he answers. No, the hungover Gawain was not at mass all night; his Marian icon of a shield
