During the days of her mortal life Bonolata accidentally gets to know about the secret of child sacrifice which Kalothakur, the priest was performing for quite a longtime in her village.
On their first encounter both ghost and the boy get intrigued and suspective towards each other as both of them could see, feel and touch each other just like normal human beings, which they are not suppose to.
Incidentally Shurjo is also the great grandson of Kalothakur who suffers from somnambulism and is brought to the village away from city bustles by his parents to have a change of air.
Bonolata also informs Shurjo only if she could sleep again and sees the dream then she would turn into an angel, freed from the bandages of the mudane world of death.
After a lot of hard work Shurjo finally reaches there and finds a notation of ancient lullaby which makes ghost fall asleep.