A newly married woman Rama (Madhabi) of a rich family faints every evening at 6 and remains unconscious for half an hour. The family psychiatrist Dr Bose (Tarun) doesn't find anything wrong and no medication works. He advises to call a para-psychologist Dr Kaul (Pran). He starts investigations and finds a strange taxi driver, who sounds horn every evening at 6 outside the music academy where Rama was regular. His taxi is always free but still he doesn't take any passenger, and drives to Victoria Memorial (Lover's rendezvous place) and at exactly 6:30 he comes out of it. At that time he too is normal and takes fare. Though Rama's father Mr Roy (Kamal Mitra) tells she didn't have any affair before marriage, but it comes out that she had one, with one of his henchmen, Ranjan (Subhendu)- Roy is a smuggler. Ranjan was a the son of a very close class-mate friend of Roy. To complicate the issue, a girl of the slum where Ranjan lived, Moyna (Kalyani) is in love with Ranjan whereas Ranjan's ...