Darjeeling-based Roy family consists of Subodh, his wife, Nanda, and their daughter, Nalini. On the occasion of Nalini's engagement ceremony with Mohan, a number of celebrations take place, including fireworks, which result in Nanda's accident, she passes out, is treated for minor injuries, and is allowed to recuperate. The next morning she wakes up claiming that she is Radha; that Nalini is not her daughter; and that Subodh is her brother-in-law. She also states that she is to get married to Ram Kumar of Bombay. Fearing that his wife is losing her sanity, Subodh first summons their family doctor, Dr. Verma, and then a Psychiatrist, Dr. Rajesh Khanna. Rajesh conducts some tests on Nanda and concludes that her brain activity is normal. Then Nanda sees a dead woman's body in her closet, which subsequently disappears when the others arrive; she also tries to kill herself - in vain. On her insistence, Subodh and she travel to Bombay to unravel this mystery - to no avail, and they return .