Dev Anand (Rajesh), a simple and poor driver cum assistant to a rich boss (Abhi Bhattacharya) in Kolkata. He is hard pressed to fund money for his sister's wedding, when out of the blue a stranger offers him money in return for playing an imposter of a brother in law for a dying old man in Darjeeling who owns a palace and of course millions worth of property.What seems like a simple task for Dev anand who is in love with another rich girl (Asha Parekh) turns out to be a vicious trap where he is caught red handed in front of a dead man, who is actually the owner of the palace but not the one Dev had been meeting there till now. Farida Jalal as the seductive nurse complicates the matters. Nothing is as it seems and it turns out to be a good whodunit mystery with Dev Anand on the run from law to prove his innocence. The identity of the real villain remains a mystery and the climax comes as a surprise.
