Hailing from the village of Dharampura in Kullu, Karuna is a nurse who starts working at Malhotra Hospital. Driven to become a nurse by the tragic death of her parents, Karuna is quiet and withdrawn, unlike the other nurses. Attentive to her work and bearing a good recommendation, she is soon assigned to the General ward. Sheela, a fellow nurse, becomes her friend.
The general ward is populated by a host of interesting characters: Girdhari, whose good humour and cheer belies his illness, the cantankerous Nathu who always refuses to take his medicine, and Rahim, a scrawny, browbeaten man. Efficient, beautiful and modest, Karuna easily becomes a favourite of the ward. Soon, she assists the resident surgeon, Dr Sushil Verma with an operation. Sparks fly when they meet, and they are both very taken with each other.
While Karuna is with the other nurses on the beach, a young girl hurts her leg while playing. Karuna takes her home, and it turns out that she is Munni, Dr Verma’s sister. Karuna is invited to stay for a cup of tea, and while talking to Sushil’s mother, she reveals that she is completely alone in the world. Sushil’s mother takes a liking to her, and tells her to visit them as often as she likes.
At the hospital, Karuna proves her mettle when confronted with the ill-tempered, foulmouthed Nathu. Her quiet resolve bears down on him, and he takes his medicine of his own accord. Sushil’s admiration for her steadily grows, and when they are both on late-night duty, they begin to spend time together. Even as love has just started to blossom between the two, Sushil and his family are called away to Kashmir: news has reached them of Sushil’s relative and benefactor, Lala Vasant Rai, being taken ill. Once they do reach Kashmir, however, Sushil is shocked to realize that this was merely a ruse. His mother and the Lala have decided to marry him to the Lala’s young daughter, Kusum. Though Sushil vehemently rejects this alliance, his mother reminds him that he is beholden to Lala for his life, and refuses to return with him unless he consents to it.
In the interim, we return to the hospital to see that Nathu has recovered, and he bids an emotional farewell to Girdhari. Karuna steps out to the balcony, and is devastated to see that Dr Verma has returned from Kashmir with a new bride. As part of the hospital staff, she is unwillingly drawn into a boat party organized to congratulate the doctor on his wedding. It falls to Karuna’s lot to sing for the party, and she uses this opportunity to subtly express her loss, alerting not just Sushil, but Sheela as well.
Karuna wishes the new couple happiness, but the Verma household is unsettled by Kusum’s arrival. Brought up in the lap of luxury, Kusum is unable to adjust to living a life on the hospital premises. On the other hand, Sushil is made uncomfortable by her ostentatious displays of wealth.
Karuna and Sushil, on the other hand, find it difficult to work in each other’s vicinity without being reminded of their brief courtship. For the 25th anniversary of the hospital’s foundation, a large ceremony is held. The staff of the hospital stage a play titled ‘Omar Khayyam’. Sushil plays the poet and Karuna his personified thought, and even on stage, the two are unable to mask their attraction to each other. Seated in the audience, Kusum begins to suspect a clandestine relationship between them.
The unhappy Kusum neglects to tell Sushil when he receives an urgent call from the hospital on an evening they have planned to spend together. They go to the club together, but Girdhari’s state worsens, and the hospital frantically tries to contact Dr Verma. He hurries back, but it is too late, and Girdhari dies. Karuna is forced by Sushil to reveal that it was Kusum who kept the call from him. He heads home in a rage, and after a terrible fight, Kusum decides to go back to her father in Kashmir.
With Kusum gone, Karuna and Sushil are driven closer together than ever, and Karuna is dismayed when she finds out that Sushil reciprocates her feelings. Guilty of loving a married man, she hands in her resignation, but Dr Malhotra requests her to stay for the benefit of the hospital. He suggests a brief change of scene instead, and assigns her to an emergency medical team being dispatched to tend to survivors of a railway accident outside town. Karuna is relieved until she sees that Sushil is to travel with her as well. Sleep eludes both of them when they take shelter for the night, and a restless Sushil heads out into the storm. Karuna finds him outside, unconscious and sick with fever. He is immediately brought back to the hospital, and when he recovers consciousness, he calls out for Karuna. Unfortunately, Kusum returns at this exact moment. Jealous and frantic, she slaps Karuna and takes Sushil home with her.
When Sushil returns to work after his recovery, he is told that Karuna has left. Nevertheless, he refuses to accede to Kusum’s demand that he quit his job at the hospital, and in the ensuing argument, Kusum leaves the house to find Karuna. Fearing the worst, Sushil follows her and is alarmed to see her driving off a cliff with Karuna in her car. He sees Karuna still conscious, and jumps in to rescue her. As he comes out of the water carrying her in his arms, it seems that the two lovers might finally unite in peace.