A famous fashion designer, Rocky Nath, is murdered at his own birthday party. Later, the police find that he was injected with a poison called procydin. The police suspect that Rocky’s fiancé Deepa is involved, as she is a chemist. The case goes to court and Deepa’s father, Mr. Bhushan, appoints K. D. Pathak as his lawyer. I. M. Jaiswal is the prosecuting lawyer and calls-in various witnesses to prove Deepa the killer. Later, it is found that the poison was prepared in his factory.