A major BBC drama about the life of Mary Corrigan, from her days as a rebellious mill worker in 1915 and her doomed love for a man who must fight for his country, to her final days in the run up to the British General Election of 1997. 'The Key' follows Mary through a lifetime of personal and political struggle, raising first her own daughter and then her grandchildren. Throughout her turbulent life though, one thing remains constant: the mystery of the key that she wears around her neck. What secret will it unlock? In contrast, Mary's granddaughter Jessie is a timid teenager, living in the shadow of Maggie, her clever and beautiful older sister. Will she fulfil her heart's desires? In 1997, in the run up to the British General Election, a stroke-ravaged Mary becomes aware that a batde concerning her welfare is about to explode. It's a battle that will test the loyalties of everyone in her family, from Helen, her campaigning daughter, to Maggie, the New Labour parliamentary candidate. And it will force Jessie to take the most courageous decision of her life, and finally discover the meaning of her grandmother's key.