Karan (Harman Baweja) and Sana (Priyanka Chopra) are a couple in love. They are about to get married in the year 2008. Then Karan's uncle, Dr Yatinder Khanna (Boman Irani), a scientist, tells them he has made a time machine. Sana wishes to travel to 2050, but before that happens, she dies. But ...