In 2003, two Aussies went into a basement with a serial killer called Jigsaw. They came out the proud creators of the biggest horror franchise ever...

The Saw series has become the highest-grossing horror franchise in history, spawning four sequels, a mound of merchandise and, most recently, a rollercoaster ('Saw – The Ride'). But how did a little movie achieve so much?

James Wan and Leigh Whannell met at film school in Melbourne in the late ’90s. “A really arty film school with lots of black nail polish and berets and guys making films about sand,” remembers Whannell (above, right).

“James would get up and show his films, and they’d be about zombies. I knew he was going to become something big.”

Together they fleshed out their own low-budget horror idea. It was designed to be ultra-cheap: no huge cast, no fancy sets, just three actors locked up in one dingy room and a handful of fiendishly nasty torture sequences.

The two friends maxed out their credit cards to shoot a 10-minute test short, featuring 'Billy' the puppet and Whannell himself wearing the Jigsaw killer’s 'jaw-trap' torture device.

Producers Mark Burg and Oren Koules at Twisted Pictures were two of the first Americans to see the calling-card short and were blown away by its fiendish intensity.

“When they walked into the office,” says Burg, "Oren looked at James and said, ‘Let me get this straight – you want to direct it?’

"Then he looked at Leigh and said, ‘And you want to star in it?’ They were like, ‘Yep.’

"Oren said, "Well, if you can do it for a million dollars, it’s green-lit. Go ahead and get started.’ They both looked at each other and were like, ‘Wow, America!'"