During the 1971 liberation war of Bangladesh against Pakistan in a remote village beside the river Modhumoti, Motaleb Mollah, a landlord and a local Muslim leader, collaborated with the marauding Pakistan army. After the death of his elder brother, Motaleb married his sister-in-law who had a young son named Bachchu, by the elder brother. There was an idealist Brahmin teacher in the village, Amulya Chakrabarty, who had some influence over the young Bachchu. The teacher had a daughter, a widow, named- Shanti. When the war with Pakistan broke out, watching a genocide perpetrated by the Pakistani soldiers, Bachchu joined the Bengali guerrilla's. The experiences of the bitter war shattered Bachchu's world of innocence. His guerrilla unit was deployed on the other side of the Modhumoti river to conduct operations against the Pakistani soldiers and their collaborators. Motaleb Mollah, spurred by the title Chairman conferred upon him by the wily Pakistani captain, continued to create havoc on the people around. With his gradual moral degradation Motaleb developed a carnal desire for Shanti. Then one day Motaleb's retainers killed teacher Amulya Chakrabarty and Motaleb forced Shanti to marry him. In the code of the guerrilla's the penalty of a collaborator was death sentence. But as Motaleb was Bachchu's father, his comrades were procrastinating. Then one evening Bachchu himself took a decision and crossed the river Modhumoti with a dinghy and a rifle and with a determined sense of mission.