Rajat Sharma is very honest custom officer, he had lost his wife and while dying she had requested Rupa an Air hostess to look after munna, her son and Kundan, Rajat's brother and while fulfilling her promise Rupa came very near to Rajat and soon they were to get married, but before that Rupa wanted to fulfill Rajat's dream of making Kundan a big doctor and a good citizen.
Rupa's route was changed to Singapore, Munna was very happy, because Rupa always brought toys for him from there-But Rajat was worried, as he was informed that diamonds are smuggled into the country from Singapore.
One day a toy broke into Rupa's hand and she was shocked to see diamonds in it, she was nervours, she threw all the diamond's in the sea, there Kundan revealed that he was the real culprit, smugglers threatened Rupa that if she did not compensated them for their loss they will kill Kundan.
In her desperate attempt to save Kundan, destiny brought her before Rajat-but as a smuggler.
Then what happens.
Can love stand between duty and loyalty? What happened to Kundan? Did love smiled again on Rajat and Rupa?
To learn this you must see Udhayam Production's "Dil Kaa Heera" to its tense and exciting climax.