Kati Patang (1971)

Madhavi (Asha Parekh) is an orphan living with her maternal uncle, who arranges her marriage with someone she does not know. Blinded in love with Kailash (Prem Chopra), she runs away from the marriage procession. She discovers Kailash in the arms of Shabnam (Bindu). Heartbroken and dejected, she returns to her uncle, who committed suicide from the setback. Madhavi realizes that she has no one in life. So she decides to leave town and head somewhere. She meets her childhood friend Poonam (uncredited) who tells her about her husband's untimely demise in an accident and she is on her way, along with her baby boy Munna, to stay with her in-laws whom she's never met before. Poonam manages to compel Madhavi to accompany her as her plight is pitiful. En route Poonam and Madhavi chit-chat until the train derails. Madhu and Poonam end up in a Government hospital. Poonam has lost her limbs. She knows that time is up, so takes an oath from Madhu that she will assume Poonam's identity, bring Munna up and continue for her in-law's house. Madhu had no choice but to obey. On the way, the cabbie attempts to rob her until Kamal (Rajesh Khanna), the forest ranger rescues her and gives her shelter until the skies are clear the next day. She soon learns that Kamal is the very man she was about to marry. Ashamed, she leaves Kamal's home and reaches Poonam's in-laws. Her father-in-law, Dinanath (Nazir Hussain) and mother-in-law (Sulochana) accept her and let her stay there. Kamal keeps visiting the house as he was the son of Dinanath's best friend. As he keeps visiting, he realizes that he is in love with Poonam.
But 'Madhavi's' jinxed fate has brought Kailash to Dinanath's house. He is after their money and is very close to reveal Madhavi's identity. To be successful, he impresses all the members of the house but Poonam takes a resentment to him. Dinanath soon realizes Poonam's true identity and asks for the truth. When he realizes what the matter really is, he accepts Madhavi and makes her the guardian of the Dinanath property which will be inherited by Munna. Before the new dawn would rise, Dinanath is poisoned by Kailash, which he mixes in his milk. Mrs. Dinanath accuses Poonam for what has happened and she is jailed. Now Shabnam enters the life of the Dinanaths claiming that she is the real Poonam. Mrs. Dinanath in rage sends her away and is ready for no story. Kamal takes a dislike towards Madhu, learning the truth. And soon he realizes what the truth is and gets Shabnam and Kailash arrested for their evil intentions and Madhavi is freed. When Kamal searches for Madhu, he realizes that she has left without any notice and left a letter for Kamal, stating that she is committing suicide. Kamal starts searching for her and finds her trying to jump from a cliff, stops her by singing a song, and they reunite.