One dismal day in 1857, Maria Mundy arrives at Hatter's Hall, the local mental asylum, not as an inmate but as a worker. Here, she is ordered to care for Isabelle Montgomery, the daughter of an influential land-owner. But Isabelle is not insane. She, like many other young women confined within the walls, has been banished here by her family. Hatter's Hall serves to hide unmarried women, in the family way, from prying eyes. As the women's lives become entwined, they realise the dangers they face. But there is only one way out of Hatter's Hall. The women must escape and there is one man who can help, Isabelle's brother Joshua - who can barely keep his eyes off Maria. Otherwise, there's every chance they might never leave.