A dangerous terrorist Wasim Khan, working towards the separation of Kashmir, is arrested by a team led by Colonel Rayappa (Nasser).
Roja (Madhubala) is a cheerful and simple girl living in a village in Tirunelveli District. Rishi Kumar (Aravind Swamy) a city-bred cryptologist working for the Indian Government, eager to marry a village girl, comes with his mother to meet Roja's sister Shenbagam (Vaishnavi). Shenbagam, who has been nurturing the dream to marry her cousin right from her childhood, requests Rishi to reject the proposal, as she does not have the guts to share her feelings with her parents, who are not on talking terms with her cousin. Rishi not only rejects her, but he also expresses his desire to marry Roja. Though Roja gets upset, her parents agree and also get Shenbagam married to her cousin as desired by her. Roja marries Rishi but does not accept him as her man as she still holds a grudge against him for refusing to marry her sister and feels guilty for taking her place. When Shenbagam clarifies all to Roja and declares that her happy life is due to Rishi's help, Roja's misunderstanding is cleared and she becomes normal. At this stage, Rishi is given an assignment to go to Kashmir and decode information exchanged between terrorists, as his boss (S.V. Venkatraman), who was supposed to go, has taken ill. Unable to bear the separation from Rishi, Roja accompanies him to Kashmir. All of a sudden, the lovebirds find themselves in a beautiful land and enjoy their stay and work there.
Roja's world turns upside down when Rishi is abducted by the terrorists to free their leader Wasim Khan from jail. Faced with the daunting task of rescuing her husband, Roja runs from pillar to post, pleading with politicians and the military for help. Meanwhile, Rishi, held captive by a group of terrorists led by Liaqat (Pankaj Kapur), tries to reason with them. Liaqat's sister is a little compassionate to him. When Liaqat's younger brother (who crosses the border to Pakistan for training along with other youths from his village) is shot down by the Pakistani Army, Liaqat's belief is shaken, but he still manages to remain committed to the cause.
All of Roja's efforts fail but she persists and manages to convince the Central Minister who attends a function in Kashmir to get her husband released. The Government, much to the chagrin of Colonel Rayappa, decides to release Wasim Khan in exchange for the release of Rishi. Rishi, not wanting to be used as a pawn to release a dangerous terrorist, gets help from the sympathetic sister of Liaqat and escapes. Liaqat and his men chase him. Colonel Rayappa, Roja, and other Army officers get to the hostage exchange spot with Wasim Khan, but the terrorists fail to show up with Rishi. Roja assumes that Rishi is dead. But Rishi manages to get close to the exchange spot on his own after evading the terrorists. However, Liaqat catches up with him and holds him at gunpoint, but Rishi's reasoning, passion for his country, and his longing to see his wife melt Liaqat's heart, who lets him go. Rishi reaches the exchange spot and gets united with Roja, whose persistence and love finally succeed.
[from the book Pride of Tamil Cinema: 1931 to 2013, by G Dhananjayan, Blue Ocean Publishers, 2014]