Filmmaker Vipul Shah's upcoming film, Waqt: The Race Against Time has been having sensational music sales, and it's April's biggest release so far.

The positive buzz around the film is generated by its starcast -- Akshay Kumar [Images], Priyanka Chopra [Images], Amitabh Bachchan [Images], and Shefali Shah -- and its unique father-son theme.

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In an exclusive conversation, Vipul reveals what the film is about:

Waqt is the love story between a father and a son. It's the most unusual story to have come on Indian screens about a father and son because it doesn't deal with the typical issues that we've been seeing. Either those films are about a generation gap between the two, or a rich boy wants to marry a poor girl and the families aren't in agreement. Waqt is not about all that.

Waqt is about the upbringing that a father gives to a kid. And that is the biggest job and challenge in a father's life. So it automatically leads to a lot of emotional conflict within the family. In this case, the characters of Amitji and Akshay are like friends, they have an extraordinary bonding. They even go to a disc (discotheque) together, that kind of a really friendly equation.

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This is the story of a very gullible father who cannot say anything to his son. And how things don't happen the way he wants and expects them to happen. What goes wrong and how it goes wrong and how he and Akshay try to resolve the situation, is what the film is about.

I am very happy and satisfied with the film. I just hope that the way I am seeing and liking the film is also how the audience will like and enjoy it.

The thing about Amitabh and Akshay (who also starred in Vipul's Aankhen [Images]) is that first of all, they're great, fantastic, superb. And here they fit the characters perfectly. The characters and the relationships between them are very much like Mr Bachchan and Akshay, and physically they look very good as father and son. So I have more than one reason to cast them. And I love them personally, so that's the most important thing.

Priyanka (Chopra) is a very professional actress and she's a very hassle-free girl. I enjoyed working with her. She's also given a tremendous performance in an unusual character for her. She usually plays a glamour-girl, but in Waqt she's playing a simple girl who's a very strong woman, and she's pulled it off beautifully. I'm very happy with her job.

Shefali (Shah, the director's wife) is a very talented actress. She's pursued the craft over a long time, and this is one character where she had to be very silent; she doesn't have too many dialogues. But she has a lot of reactions and silent looks which were very important to the overall texture of the film. And I wanted somebody who's not been paired with Mr Bachchan. He suggested that we try Shefali. What she's done to the character, I think, is just amazing.

The age difference between them is hardly there. The promos have been on air and people have loved them as a pair; people are calling me up and telling me that it's a very fresh looking pair. Something that is adding a lot of freshness to the overall setup. That's what we had assumed and we're happy that it's how people are receiving it.

Waqt is called The Race Against Time because there is a target that both father and son have set out to achieve, and for that they've got limited time. So there really is a race against the clock. If they don't achieve their targets in that time, life will take a very disastrous turn. They each have their own target.

I wouldn't like to call it a comic or a dramatic film. If I have to sum it up in one line, I'd just say it's a film done straight from the heart. And the effort is to connect with the hearts of the audience, not the minds. It's not a mindless or senseless film, it has a very realistic and relatable story and every father and son will be able to identify with it. There is a lot of humour, drama, emotions, glamour and dances and songs, everything is there, but still Waqt is straight from the heart.

As told to Raja Sen