 Sanjana and Avinash live in Calcutta, India, with their only child, a son. One day Avinash witnesses a crime being committed and comes to the assistance of the victim, and takes him to hospital. This does not auger well with his assailants, and they kill Sanjana and abduct their child. The police are involved, but unable to trace the child. A heartbroken and desperate Avinash decides to take matters in his own hands and begins inquiring. His inquiries take him to Bombay via the Calcutta Mail, and this is where he will find out whether his son is alive or not, or he himself has been lured into a deadly trap.