Vidya Balan plays Shobana
Shobhana played the role of Ganga who comes to visit her husband (Suresh Gopi's) ancestral house. However, she is possessed by the spirit of a famous bharatnatyam dancer Nagavalli of ancient times. A king had kept her in captivity after murdering her lover Ramanathan. So Nagavalli is out to seek revenge from the descendents of the king.
Shobhana did a marvelous role; portraying two characters at the same time. Sometimes she behaves like Nagavalli and starts speaking in Tamil, a language not know to her, while at other times she is just Ganga, a normal human being. Dr Sunny Joseph, (Mohanlal) terms it as a case of split personality.
Shobhana won the prestigious national award for her role. Vidya Balan steps in Shobhana's shoes. She plays Avni Chaturvedi. Though we don't expect her to get a national award, but we do hope to see a commendable performance.
Also read: Vidya: Don't believe in ghosts