Will The Bourne Legacy work without Matt Damon?

Fans of 'Bourne' will know Matt Damon quit the spy franchise when 'Supremacy' and 'Ultimatum' director Paul Greengrass decided against making a 'Part 4' in 2009.

Studio Universal pressed on regardless, bringing in Tony Gilroy to direct a re-tooled installment, and most bizarrely signing up a new star in the shape of Jeremy Renner.

[Related story: Renner reveals how he got the Bourne role]
[Related story: Ed Norton baffled by Bourne lingo]

He plays Aaron Cross, another biologically-meddled-with superspy who goes rogue when Ed Norton's creepy government agent decides to "roll up" his training program… by killing everyone involved.

Some felt the re-casting was cynical, a way for the studio to milk the last dollars from a franchise that should have ended when Damon (spoiler alert) made that jump into the river at the end of 'Ultimatum'.

Watch what the cast had to say:

"Anybody would think 'how do you do a Bourne movie without Jason Bourne?'", star Jeremy Renner admitted to Yahoo! Movies.

The cast however insist that 'Legacy' is a worthy follow-up to Greengrass's trilogy, and a natural expansion of the 'Bourne' universe.

Ed Norton said: "This isn't like casting Andrew Garfield as Spider-Man and starting over.
"I think that fans of the series will find this extremely un-cynical. This feels like a very authentic and positive expansion of the story. It doesn't try to sell you a cheap bill of goods."

[Related story: Bourne tops best conspiracy movie poll]

Director Gilroy, who helped write all the 'Bourne' flicks, understood fan concerns.
"It's not that cynical kind of series where you can replace him or change him or do a prequel or any of those things. [After the original film collapsed] we came back a couple of weeks later and thought you could say this was a small part of something much larger and kick the door open and see what's outside there."

It's this central conceit, that Jason Bourne's Treadstone program was part of a wider network of super-spy initiatives, which drives 'Legacy' and could potentially see Matt Damon return at some stage. It's a tantalising prospect first raised by producer Frank Marshall, and Ed Norton can see it happening.

"You can see them all swirling back together again" he said.

Does Bourne work without Bourne? See for yourself when the film is released on Monday August 13.

Watch the trailer below: