Bakso, A mysterious box

Two friends, Biswas Babu and Banerjee Babu. One day Biswas Babu bought an old box from a shop and returned home in the evening. Being very tired, he went to bed without seeing the box. In the morning a boy comes to her house, with a letter given to him by his younger brother. There in the letter he asked the boy to keep for housework. The boy did not have one arm. Yet Biswas Babu left the boy for work. That night Biswas Babu heard a sound. Hearing that, he asks the boy if he has heard. The boy's name is Natwar. Natbar then said that he could not hear any sound. Then Biswas Babu finds the source of that sound and sees that sound coming from the box. Then he opened the box and saw a piece of cut hand. After watching the short film you will know what happened then .