Mmmm… Karthik, played by farhan Akhtar, is an introvert and a shy boy by nature and choice both. Being closed within himself he suffers with huge confidence issues and is unhappy with his not so impressive job that gives up not so immpressive results.

On top of it his boss treats him like a left over. Nut what exiting in his life is Shonali. Shonali is his colleague, he loves secretly her. But on the other hand she doesn't even know that he exists. Karthik is a big time loser, and he knows it, and has no issues with accepting it.

Karthik accept the truth that his life worsest of all and then suddenly one night, life opens the door in a very mysterious way and the phone rings. The call is from someone he never thought of. The call is from from Karthik or say the person on the phone claims to be Karthik. And he says he is here to change Karthik's life.

Karthik invites the change from the phone in his life and in a little while the phone becomes his guide, his mentor, friend or say guardian. And above all it becomes the green card to the love of his life, Shonali and his life changes in ways that he even have never ever imagined.