The film opens with the preparations of the marriage of Anand (Sanjeev Kumar) and Karuna (Sulakshana Pandit in her debut role). Amidst all the fun and gaiety, Brij Bhushan (Ranjeet) corners Anand's sister, Kamla (Farida Jalal) and blackmails her about some love letters she had earlier written to him. The odious man asks her to meet him in his hotel room at 8 pm or elsehe would hand over the testimonies of their earlier affair to her husband. This would surely bring her and her family ruin. Kamla is distraught with this development and runs to Karuna who is getting ready. She tells her everything. Karuna being the good Samaritan offers to get the letters from Brij Bhushan by going to the hotel room herself. This is dangerous. She is the bride and any delay would malign her forever but she wants to help her friend Kamla. So she goes wrapping herself with a shawl.
While escaping with the letters, her shawl gets stuck in one of the drawers. Panic stricken she tears the shawl before leaving with the small part stuck in the drawer. Even in the taxi, she drops one of the letters while paying the cabbie. Karuna is a simple girl who is not suppose to be here so it's a given that all these goof-ups will occur. And understandably all these loose ends will not escape the eye of the law.
Especially when the sharp legal eye belongs to Anand, Karuna's husband! That means right from the very beginning Karuna is living with the hawk who will pull all stops to nab the killer. The investigation drama is interesting. Karuna is the loving and doting wife who is also naughty at time. But whenever the topic of Brij surfaces, you can sense her discomfiture. She is always at tenterhooks as to what will become of her. She killed Brij to defend her honour and to help Kamla but who will listen to her? Who will understand that she is not a cold-blooded murderer.
There are numerous scenes in the film that are worth mentioning. Apart from the romantic scenes between Sanjeev Kumar and Pandit. He is effortless and she isn't bad either. But the scenes focusing on Kumar tightening the noose around the killer are very good. Like how he deduces certain things and how when he comes to realise that his wife just might be the killer, his pained expression is remarkable. But with Kumar, you can expect only a good performance.
Kalyanji Anandji's music fits the purpose. I think there a naughty flavour to Subah aur shaam. It's coquettish tone hides it original intention; to distract the hawk detective from discovering an important clue regarding the murder. This is the only song that I actually remember. The other songs were just about okay.
Aprt from the story there are other connections between Kangan and Uljhan. Ashok KUmar who played the male lead in the 1959 film, is Anand's father Kailash Chandra in Uljhan. Like Nazir Husain in Kangan, he helps in vindicating his daughter-in-law.