Joan Stanley may think that she's enjoying a peaceful life of retirement in 2000, but when MI5 turn up on her doorstep and accuse her of providing intelligence to Communist Russia in earlier life, her world is flipped upside down.
Red Joan sees Judi Dench and Sophie Cookson both star as the central character; the older and younger versions of Joan respectively.
Audiences will flash back to Joan's life in 1938 as a physics student in Cambridge who falls head over heels for a young communist; a man who allows her to start seeing the world in a new light.
Then working at a secret nuclear research facility during the Second World War, Joan is confronted with the impossible question of exactly how far one person would go to ensure peace, and resist the destruction of the world.
Will she betray her country for what she believes to be the greater good? Or will she work to ensure her loved ones will be saved, no matter the price?
Directed by Trevor Nunn and produced by David Parfitt, the film also stars Stephen Campbell Moore, Tom Hughes, Ben Miles and Tereza Srbova.
Red Joan comes to cinemas across the UK on April 19, 2019.
Tagged in Dame Judi Dench