Some thought “Kalo Korta” was a dacoit, some thought he was a friend of the poor. Inspector Singh was entrusted to arrest that peculiar man. Failing several times he depended on friend Suryakanta Roy. Suryakanta was a famous detective story witer. Mr. Singh got the news that famous private investigator Bimal Bose had accepted the hospitality of millionaire Mr. Chowdhury in Delhi. On his request Surya went to Mr. Chowdhury's house and requested Bimal to accept the case. Next day the valuable necklace of Mrs. Chowdhry and Rama, niece of Mr. Chowdhury were lost from the party. After the party it was found that Surya Roy was smiling with the two necklace in his hand. Beside him there was street girl Munni. Surya had given her shelter and educated her. The buyer of the two necklaces came. But Kalo Korta could not sell of the necklace of Rama. Mr. Chowdhury had became rich depriving her niece Rama from her property. That night Namita came to console Rama. Namita met Kalo Korta in Rama's room. But she could not find Kalo Korta after he returned the necklace to Rama. Getting the telephone Bimal rushed to Mr. Chowdhury's house. Hearing everything he went to Surya's house with Mr. Sing. But he was not found. At that time Surya Roy, alias Kalo Korta, was inside a compartment of a running train. He was busy in helping the workers of Mr. Chowdhury’s factory. But before he reached his house Bimal Bose had already surrendered Surya's house by the police.