Mohan and Sohan are the two sons of a police officer. Their father has received death threats from a crook named Ranjit Singh. One night Ranjit Singh’s henchman stabs him in full view of his two sons. While Sohan is traumatised by the incident and stays by his dying father, Mohan pulls the dagger out of his body and gives chase to the assailant. During the chase, the assailant runs right into the dagger in Mohan’s hand. Confused and scared, Mohan hides in a car that belongs to Ranjit Singh and is ultimately discovered.
Mohan grows up to be called Moti, the right hand man of crime kingpin Rai Sahab Bhupinder Singh. Sohan follows his father’s footsteps and grows up to be a debonair police officer. Sohan goes undercover, in the guise of a small time crook named Johny to trap Heera, a smuggler working for Bhupinder Singh. The trail leads him to a beautiful woman named Rekha who hires him for a job which soon takes him to Kathmandu. In Kathmandu, they meet Moti. Moti is initially suspicious of the smooth-talking Johny but comes to trust him. As the plot thickens, Johny finds out that Rekha is actually Bhupinder Singh’s daughter. She is trying to figure out why her father turned into a criminal by infiltrating his smuggling ring. Johny and Rekha decide to help each other in order to reach him. Moti, however, is the only one who knows Bhupinder Singh’s actual whereabouts. After Johny manages to ingratiate himself enough he is introduced to Bhupinder Singh. Rekha is unwilling to believe her father has turned into a lecherous and unscrupulous criminal. She sneaks into Bhupinder Singh’s mansion one night, only to find out that the real Bhupinder Singh has been usurped by his brother Ranjit Singh. She is discovered and taken prisoner by Ranjit Singh.
The convoluted plot reaches its resolution when Moti and Johny realise that they are the long-separated brothers. The two join forces with the Bombay Police Commissioner to foil the man who had murdered their father.
The film was a massive hit, proving that the formula struck upon by Dev and Vijay Anand in Jewel Thief (1967) was quite effective.