In 1918, Sir Harold Nicolson and Vita Sackville-West are a golden couple. He is destined for a high rank in the diplomatic corps; she is the daughter of Lord and Lady Sackville, a successful novelist and creative gardener in her own right.
They are also both part of the famous Bloomsbury Group.

However, five years in, their marriage is about to reach crisis point. Harold confesses to having affairs with men, but swears his only true passion is Vita. She accepts this, but when her childhood friend Violet Keppel arrives, declaring her love
for Vita, the two women find themselves in an intense sexual relationship.

As their affair becomes more passionate and all-consuming, the tension rises in Vita and Harold's marriage. While he is torn between his love for Vita and his hatred for her lover, she is seriously considering jettisoning her social and material status and eloping with Violet to live together in Paris...