On the outskirts of Nuneaton stands Hatters Hall, a dark forbidding place, once a home for the mentally insane. On a rainy dismal day in 1857, Maria Mundy arrives at Hatters Hall, not as an inmate but as a worker. There she is ordered to care for Isabelle Montgomery, the daughter of an influential land owner, and as their lives became entwined the life Maria had known is destined to change for all time.