The police discover a stranger in a cell closed for 50 years. The life of Jailer Mostak Ahmed, under various pressures from his family and superiors, becomes more miserable.
The prison authorities fail to understand how the stranger entered the cell. In addition, everyone begins to fear him, and various speculations are born out of this ambiguity.
The jail authority secretly brings in a sign language interpreter to communicate with the stranger. The stranger claims that he has been in prison for 250 years.
The inmates begin to address the stranger as 'Gazi Peer'. Gazi Baba pronounces people guilty or innocent just by looking at their eyes. Meanwhile, it is revealed that Gazi Baba has come from a secret prison in Andaman.
Gazi Baba's prolonged interrogation enrages his followers. Deputy Jailer asks Mostak, what if the widely known story about this cell happens again?
Mostak Ahmed and Gazi Baba face each other. Unable to control his temper, Mostak raised his hands on him.
Raju, a prisoner who got caught thanks to the powers of Gazi Baba, is extremely angry with him. On the other hand, Mostak and the Deputy Jailer count hours till night when they will finally find answers to their questions.
While searching for her father, Maha learns Mystery Man's true identity. On the other hand, Raju and Mystery Man discuss that they don't have much time as there will be a prison shift.
Raju instigates Gulzar as per the plan. Meanwhile, Maha brings Mostak to Mystery Man, who says he will find Ataur only on one condition.
The pragmatic Aslam is on to Gazi Baba, and the latter's followers are on to Aslam. While Maha falls into a deep conflict, Gulzar doesn't believe the sneaky Raju.
Mostak wants to get Sajib out before he is transferred to another jail. A helpless Maha goes to Mystery Man for help.
Ashfaq questions Maha's closeness with Mystery Man. Gulzar and David have a face-off. When everything seems to be under control, the message to abort the mission arrives.
The Secret Group keeps its promise. Maha finds her father, and Mostak finds Ataur. But will Mystery Man follow the instructions given by the Secret Group?
Even though the Secret Group has aborted the mission, the mission continues inside the prison. According to Plan B, Raju instigates Murad and Gazi Baba's followers. Now everyone waits for the final bell.