A female role centric movie, Bandini revolves around Kalyani or Bandini (meaning imprisoned). She is in a prison in India. How could she commit a crime? We learn the circumstances in flashback. Kalyani falls in love with a freedom fighter/anarchist - Bikash (Ashok Kumar) during the British Raj, who latter leaves her in the village promising to come back but never does. The society treats them the best way it could in the situation, the family is the butt of mockery. Broken by her father's misery and that of her own, Kalyani moves to the city, to the singing of the "O jaanewale ho sake to laut ke aana". In the city she works as a caretaker of an almost insane woman, who is also the wife of Bikash. When Kalyani is told her father came to the city looking for her and died in an accident she decides to poison her lover's wife, identifying her as the cause of her miseries. Bimalda captures her emotions with light and darkness falling on her face due to a welder's torch and the thumping of Iron in the background.
Back from the flashback in the jail Deven (Dharmandra) the jail doctor falls in love with her. Kalyani is not ready for it and starts to stay away from him. They are always shown with a partition in between after Deven proposes her. Another symbolism used in the movie is the occasional shouting of "All is well" by the prison guard when nothing in the movie is.
The lines "Main Bandini Hoon Piya ki, Main Sangini Hoon Saajan ki" in the end score of the movie tells us that Kalyani is imprisoned by her love. "Mere saajan hain us paar" is sung by the musician S D Burman himself. The climactic song, it beautifully expresses Kalyani's dilemma of having to choose between Bikash & Deven. Though the movie features excellent songs they all depict the situation like nothing else could. This should not be looked upon as the traditional dance and sing Indian style of cinema. Without wanting to add more spoilers in my comments I will give some little details.
The character of Kalyani gets lifted from that of a woman who is a prisoner of destiny to one who defines her own freedom
Nutan is considered the finest actor in Indian Cinema. Nutan is strongly supported by Ashok Kumar, whose flawless performance matches Nutan scene for scene and Dharmendra, just beginning to make an impact in the film industry. Bimal Roy is another one of the best. He won eight filmfare awards in his career the last one for Bandini and the first one for "Do Bigha Zameen" (which incedently was the first filmfair award). S D Burman is another one of the best. The songs are sung by Mukesh, Lata Mangeshkar, Asha bhosle, Manna Dey and S D Burman again all of them are either the best or one of the best singers. Bandini is brilliantly photographed by Kamal Bose with its rich tonal quality and evocative framing.