'Kaal Ratri' is the story of a cursed night on which a poor man's daughter Savitri is raped by local youths including the son of the school principal. The principal rescued the girl from his school, took her to the police and then got her admitted in the hospital. When Satya Bhushan finds out that his son is one of the culprits he gets a serious heart attack and is hospitalized. When he regains consciousness he tries to get the culprits punished. He keeps fighting despite the threats of the politician and his wife's requests. But all his efforts prove to be futile when the victim withdraws the case and false medical reports are procured which prove that she was not raped. He resigns from the post of the principal after he is discharged from the hospital.