During the London Blitz, nightclub singer Vera Phillips runs into her first love, charismatic Welsh poet Dylan Thomas. Although Dylan is now married to Caitlin Macnamara, with whom he has a son, he and Vera rekindle feelings for one another. The two women, initially rivals, become best friends. Drinking heavily in wartime London, the three come to get along.
William Killick, a British Army officer, begins to pursue Vera. Both Vera and Caitlin are intrigued by his steadfast, gallant personality despite its contrasts with Vera's rebelliousness. William notices Vera's closeness to Dylan, but doesn't appear concerned; he and Vera even lend the struggling poet some of their savings. William and Vera fall in love and marry. Soon afterwards, William is called up to fight against the German invasion of Greece after the Italians failed.
Shortly after William's departure, Vera discovers she is pregnant. Upset that motherhood will take away her independence, she contemplates aborting the child but cannot bring herself to do so. She gives birth to a son and moves to the Welsh seashore with Dylan and Caitlin to raise their children in two small neighbouring cottages. Vera and Caitlin's friendship grows stronger while Dylan and Caitlin's marriage becomes distorted by multiple infidelities. Dylan draws Vera into an affair with him.
William returns a captain, scarred by the horrors of the war. Vera notices his emotional distance and instability. William suspects his wife of infidelity and confronts her. Vera confesses to both William and Caitlin, who are furious with her. One evening, while severely inebriated and angry with Dylan's friends for their ignorant remarks on the war, William wanders outside and fires multiple shots into Dylan and Caitlin's home. He does not hit anyone, and Vera calms him down. The next morning, William seems to have returned to his former self. However, he is arrested and taken to trial.
During the trial, Dylan testifies against William and distorts the facts, claiming that William was sober and intended to kill Dylan, Caitlin, and their child. The jury finds William innocent of intent to murder. After returning home, William accepts his new role as a father, and he and Vera forgive each other. Their relationship improves. Soon afterwards, Dylan and Caitlin move out of their cottage. During the farewell, Vera restores her friendship with Caitlin, but she never speaks to Dylan again, unable to forgive him for testifying against her husband.
Keira Knightley as Vera
Sienna Miller as Caitlin Thomas
Cillian Murphy as William Killick
Matthew Rhys as Dylan Thomas
Lisa Stansfield as Ruth Williams
Graham McPherson as Al Bowlly
Camilla Rutherford as Nicolette
Alastair Mackenzie as Anthony Devas
Richard Dillane as Lt Col David Talbot Rice
Huw Ceredig as John Patrick
Simon Armstrong as Wilfred Hosgood
Rachel Essex as Mel
Geoffrey Beevers as Registrar
Ben Batt as Sergeant
Paul Brooke as Mr. Justice Singleton
Nick Stringer as PC Williams
Anthony O'Donnell as Jack Lloyd
Rachel Bell as Midwife
Anne Lambton as Anita Shenkin
Karl Johnson as Dai Fred
Richard Clifford as Alastair Graham
Rick Cord as ARP warden
loosely based on real events and people, drawing on Rebekah Gilbertson's idea and David N. Thomas' 2000 book Dylan Thomas: A Farm, Two Mansions and a Bungalow