Plot

A Darjeeling-based singer is asked to impersonate and take over the life of a Calcutta-based China Town gangster.

Mike is a dreaded gangster in love with dancer Suzi and works for Joseph Wong at Chinatown in Calcutta he gets badly injured during a police chase and is arrested.While in Darjeeling Shekar a club singer in love with Rita but her father is against their relationship as he sings in clubs.When Rita travels to Calcutta Shekar follows her and her father gets him arrested for chasing his daughter Inspector Dutt is shocked to see Shekar as he is exact look alike of Mike.Dutt convinces Shekar to help him in catching the gang of smugglers led by Joseph Wong and his boss,Shekar gets trained as Mike and is ready to enter their gang.But soon Shekar's mother reaches Calcutta and he tells her about his new job where she discloses him that Mike could be his long lost twin brother Shankar who was kidnapped by goons of Chinatown 20 years back when their father had found about illegal' activates happening at the place.—alex.mjacko@gmail.com

Singer, Shekhar, lives in Darjeeling with his widowed mom, and is in love with Rita, the daughter of wealthy Rai Bahadur Digamberprasad Rai, who dislikes him, and wants his daughter to marry a wealthy Calcutta-based businessman, Chowdhry. Rita asks Shekhar to get a better career, but he refuses, so she and her dad re-locate to Calcutta. Shekhar follows them, and an enraged Rai complains to the police, who arrest Shekhar and hold him for questioning. It is here that Shekhar will secure employment with the police as an undercover agent to impersonate his look-alike, a China Town gangster named Mike, who is being held by the police, but refuses to divulge any information. Shekhar accordingly takes over Mike's life, but not for long - as Mike soon escapes from custody and is on his way back to reclaim his life.—rAjOo (gunwanti@hotmail.com)

Shekhar (Shammi Kapoor), a young singer, lives in Darjeeling with his widowed mother. Shekhar earns a living by singing in bars. He is in love with Rita Rai (Shakila), the only daughter of the wealthy Rai Bahadur Digamber Prasad (S. N. Banerjee). Rai does not approve of Shekhar and wants his daughter to marry a wealthy Calcutta-based businessman named Chowdhry. Rita asks Shekhar to get a better position, but Shekhar is quite satisfied with his singing career.

Digamber believes that if Rita stays in Darjeeling, she will continue to meet Shekhar, and so Rita and her father relocate to Calcutta. Digamber wants Rita to get engaged ASAP in Calcutta. Shekhar follows Rita to Calcutta. Shekhar tells his mother that he is relocating to Calcutta to build his career as there is no opportunity for singers in a small town like Darjeeling. Shekhar disguises himself as a religious wanderer and enters Digamber's first-class compartment with Rita. Shekhar is caught when his fake beard come off after a little while.

Shekhar comes over to Rita's house to meet her in secret. Digamber finds out and captured Shekhar through his servants An enraged Rai complains to the police, who arrest Shekhar and hold him for questioning. Shekhar claims that Rita is also in love with him, and they both want to get married as consenting adults.

However, the police notice his resemblance to a China Town gangster named Mike (also played by Shammi Kapoor), who they are holding in custody. Mike was captured after a lengthy car chase, after he was caught red handed dealing in illegal articles at the city docks. Mike's gang leader is Joseph Wong (Madan Puri). The gang operated out of China Town. Suzy is Mike's girlfriend, who dances in a bar. Mike has very distinctive mannerisms including the way he dismisses people with a swish of his hands.

Because Mike refuses to talk (he is tortured as well as lured with bribes such as imported liquor and wines, but he is adamant that he cannot be bought), the police convince Shekhar to impersonate him in order to infiltrate the Chinatown criminal ring. They offer him a lot of money & a respectable life to cooperate with the police and Shekhar agrees so that he can finally get Rita. Meanwhile the police commissioner Dutta (Kanu Roy) show films of Mike's mannerisms to Shekhar in order to train him. Dutta tells Shekhar that Mike operates out of a bar called the Blue Dragon in China Town. He is also trained about Mike's inner circle such as Suzy and Wong. Dutta says that Shekhar's mission is to uncover the way the gang works and gather evidence of their illegal activities, so they can be arrested. Dutta also wants to know the identity of the man who owns and funds the entire operation.

Meanwhile, Shekhar's mother comes to Calcutta to meet him. Shekhar tells her about the assignment that he is going to start for Dutta. Shekhar says that in exchange he will get the job of a police officer. Shekhar's mother (Mridula Rani) reveals to him that Mike may be his long-lost brother Shankar, kidnapped by gangsters as a boy. Shekhar's dad Ramlal used to play the violin in China town and drug smugglers used to smuggle drugs in his instruments. Ramlal was oblivious to this. One day Shekhar's dad found out and he refused to cooperate anymore. He reported the matter to the police. In retaliation Joseph Wong took away one of Ramlal's son Shankar. Ramlal returns home and leaves to find Shankar and never comes back. Shekhar accordingly takes over Mike's life. Police place a story in the news that Mike is in hospital and has turned a government witness, so gangsters from China town rescue Shekhar (impersonating Mike) from the hospital.

Shekhar claims that he doesn't remember details of his life due to the torture and the lack of sleep in custody. A gangster finds Shekhar spying and rings the alarm bells, but Shekhar kills him in time and claims he was the who was spying, and Shekhar/Mike pressed the alarm. Shekhar passes on the evidence to Inspector Dutt. He meets Rita and explains his true situation to her. Shekhar/Mike continues to pass info to the police via a fakir stationed right next to Mike's hideout. This leads to raids and arrests of several China Town's drug customers.

But there is one thing he and the police overlooked - namely Mike - who escapes from police custody with the help of Rita, who mistakes him for Shekhar. Mike was being transferred to the hospital in an ambulance when it crashed. Mike escaped in heavy rain and runs into Rita who takes him home. Mike understands that Shekhar has replaced him in the gang and tricks Rita into going with him to the hideout.

Mike's girlfriend Suzy (Helen) finds out Shekhar's true identity. Ching Li is a gang member who figures out that arrests and raids have increased since Mike returned. He also notices small things like Mike not remembering key people and addresses and his shoe size has also changed. Ching Li attacks Shekhar and Shekhar kills him. Suzy is a witness to everything. Suzy spares Shekhar when he reveals that Mike is alive and captured by the police and sympathizes with him after learning that Mike was his long-lost brother.

The gangsters overhear this and capture Shekhar, his life is only spared after Shekhar tells Mike his true background. Suzy confirms Shekhar's story and adds that Shekhar never touched her posing as Mike, even though he could do whatever he wanted. The two brothers capture the gang's leader Joseph Wong and the mystery boss who turns out to be Chowdhry (whom Mr Rai wanted to get Rita married to). As a result, Shekhar gets a permanent police job that allows him to marry Rita and Mike receives a reduced sentence of three years.