Bollywood is famous for its dance routines, dramatic visuals and songs across the world.

But India's most popular movie industry also produces films that initiate social debates on issues that matter to the country. Aamir Khan's PK is one such movie.

It questions superstitions in a country where religion is deeply rooted in social consciousness of the people.

Khan plays an alien in the film who comes to visit the earth and almost immediately falls victim to human greed.

His "remote control" - a device without which he cannot go back to his planet - gets stolen.

From that moment, he embarks on a journey to discover the world. He meets people, "both good and bad", visits places and learns the language.