Bomkesh and his friend Ajit laze around one morning when Mr. Nishikanta Sen, a retired Judge come to visit them. He informs that he has been given a threat by an unknown and wants Bomkesh to look into the matter. He invites them to his estate in Golap Colony, a village slightly away from Kolkata. Bomkesh decides to go there in the disguise of a Japanese and meets a lot of people with varied personalities. Some of them are Mr. Sen’s wife, his old friend, his nephew, his acquaintance, his servants, a loner, the local village fishermen, his wife, a castaway and a handicap. Soon after his visit, Mr. Sen is brutally murdered in his house. Bomkesh is officially summoned by the police and he formally takes up the investigation. The next day, the handicapped man is killed too. Bomkesh interviews all of them, digs out the past of a few people, follows some people in disguise and in the end is able to identify the killer. He gets the final clue of the murdered from his dear friend Ajit.