In June 1939, American president Franklin D Roosevelt (Murray) hosts the British royal family at his country house in upstate New York on their first-ever visit to the United States. King George (Samuel West) and his Queen's Consort Elizabeth (Olivia Colman) are on a diplomatic mission to secure America's support in the fight against Hitler. Meanwhile, against the backdrop of this historically momentous meeting, the ageing but eternally-philandering Roosevelt finds time to seduce another of his house guests, his demure distant cousin Margaret Stuckley (Laura Linney). Olivia Williams co-stars as the long-suffering Eleanor Roosevelt.