PRESS ASSOCIATION -- Zack Snyder's Superman movie Man Of Steel, starring Henry Cavill, will see Clark Kent debating whether to become a superhero when the world comes under attack.

The plot of the Warner Bros film has been revealed online as ComicBookMovie.com reports local people in Vancouver are being invited to audition as extras for the film when it begins shooting there in October.

The synopsis for the much anticipated action movie reads: "In the pantheon of superheroes, Superman is the most recognised and revered character of all time. Clark Kent/Kal-El is a young twentysomething journalist who feels alienated by powers beyond anyone's imagination.

"Transported to Earth years ago from Krypton, an advanced alien planet, Clark struggles with the ultimate question - Why am I here? Shaped by the values of his adoptive parents Martha and Jonathan Kent, Clark soon discovers that having super abilities means making very difficult decisions.

"But when the world needs stability the most, it comes under attack. Will his abilities be used to maintain peace or ultimately used to divide and conquer? Clark must become the hero known as 'Superman,' not only to shine as the world's last beacon of hope but to protect the ones he loves."

The film, currently shooting on location in Chicago, will have an all-star cast including Kevin Costner and Diana Lane as Clark's parents, Amy Adams as Lois Lane, Laurence Fishburne as Daily Planet editor Perry White and Russell Crowe as Superman's biological father Jor-El.