Set in rural Wales and 1940s London, this biopic tells the story of the romantic complications that arise between Welsh poet Dylan Thomas (Matthew Rhys), his young wife Caitlin (Sienna Miller), his first love Vera Phillips (Keira Knightley), and her husband William Killick (Cillian Murphy). Dylan Thomas, having been diverted from active duty in the Second World War and employed by the government to produce propaganda for Whitehall, reconnects with his old flame Vera while working in London. Despite his marriage to the feisty Caitlin, Thomas resumes his passionate relationship with Vera. Unusually, despite being rivals in love, Caitlin and Vera form a strong friendship when they meet, and Caitlin continues to indulge in her own extra-marital entanglements. But Vera's marriage to her devoted admirer William, and the effects of the ongoing drama of World War Two, eventually put paid to the unconventional harmony of the bohemian menage a trois, forcing events to a dramatic and violent denouement.