Four remarkable women, once pivotal codebreakers during World War II, struggle to reintegrate into civilian life in 1952 Britain. Susan, Millie, Lucy, and Jean have set aside their achievements, but Susan's discovery of a hidden code linked to an unsolved murder reignites their skills. Faced with skepticism from law enforcement, she turns to her former colleagues for help. Together, they embark on a quest for justice, blending their talents to unravel the mystery. The Bletchley Circle captures the spirit of resilience and camaraderie among these unsung heroes in a changing post-war society.