In Benaras, Ratikant Choudhury invites them to a party thrown by zamindar Dipnarayan Singh at his residence to celebrate his recovery after a prolonged illness. But the very next day , Dipnarayan dies under suspicious circumstances. Byomkesh takes the responsibility of investigating his murder. He is clear about two motives -money and an illicit relationship. The list of suspects grows, even as Byomkesh discovers the painting skills of Dipnarayan's wife, Shakuntala , through a portrait of Dushyanta and Shakuntala drawn by her.The painting haunts him, though he fails to understand why . Then he comes to know about Dipnarayan being bed-ridden for long and Shakuntala's pregnancy . Here comes the twist -a mysterious love affair. "Who is the lover of Shakuntala and the murderer of Dipnarayan? Through a spine-chilling series of events, the mystery unveils at the end.