Throughout the series, fans learn of how Ratched and Edmund were fostered as young children by the same family.
Once Edmund had escaped the prison, the series jumped forward in time to three years later, in 1950, when Ratched was living in Mexico.
She had left her job at the hospital and had moved away to spend time with her girlfriend Gwendolyn Briggs (Cynthia Nixon) who had managed to beat breast cancer.
Executive producer Alexis Martin Woodall explained why the series was set just after World War 2.
He said: “What I love about the series is that it’s not just about women. And it’s not just about the war and it’s not just about mental health.
“It’s also about marginalized groups and how we can better help communities early on.”
The series also takes a look at mental illness throughout medical history, and what fans find most unsettling is the new experiments taking place at the hospital.