Alan Garner's 'The Owl Service' meets HAL from '2001: a Space Odyssey' in an orgy of blood, lust, incest, magic, bestiality, shape-shifting, murder, betrayal and power struggles. What else would you expect when a tale from Welsh mythology is transported to an abandoned space craft Gwyneth Lewis re-imagines wonderfully the tale of Lleu Llaw Gyffes and Blodeuwedd for a modern audience.