LOS ANGELES — "The Bourne Legacy" is a work of fiction, but the scientific, political and corporate partnerships it depicts are very real.

Tony Gilroy, a writer on the first three "Bourne" films, based on the Robert Ludlum series, and writer-director of this latest installment, spent countless hours immersed in military and intelligence research to tell the story of CIA assassin Jason Bourne.

When tasked with expanding Bourne's universe for "Legacy," Gilroy again looked to reality: Hundreds — if not thousands — of secret government and quasi-government programs funded by millions and millions of dollars with little oversight, all designed to build better weapons and better soldiers.

Such advancements are at the heart of "The Bourne Legacy." Jeremy Renner plays Aaron Cross, a super agent who has benefited from the government's top-secret medical research; Rachel Weisz is the doctor who helped develop the science; Edward Norton acts as the kingpin, a sort of corporate-military-intelligence hybrid, who tries to control it all.

Gilroy talked about his inspiration for the story and why truth can be stranger than fiction:

Q: How did you go about broadening the "Bourne" world?

A: There needed to be a pulling back the curtain, a much larger conspiracy. Edward Norton has his agency that he's carved out there at the center of the Beltway, and (we) found a niche for him in the military-industrial-corporate espinocracy food chain ... It has all of the funding and all of the motivation and all of the secrecy that we would expect with a government program, but then it has all the lack of oversight, the human error, that we know always comes with everything. ...

Q: Did you discover anything so far-fetched that moviegoers might not believe is true?

A: I wanted to keep everything really kitchen sink-y and crude and authentic and real and did not want to have it feel science-fiction, and I knew that what we were talking about is really on the way here or certainly a lot of people have it up on the chalkboard. ... The thing that seemed most applicable to me and that helped me most in my story was gene doping, genomic alteration. That was a little bit sexier and a little more on the horizon than some of the other things. It's kind of fascinating, in the last month, since the Olympics have come up, I've seen two mainstream articles — the scientists who are responsible for doing all the drug testing for all the athletes, that's their cutting edge. That's their next (question), how do we monitor gene doping. And they don't know how to do it, and it's really fascinating. The scenario is they introduce chromosomal gene doping through a synthetic virus. And that's happening now. That's what Olympic doctors are worried about ... .

Q: Writing the three previous "Bourne" movies must have made stepping into the director's role more thrilling.

A: With the trepidation of not wanting to have people think that you're doing science fiction. We're not really going for any suspension of disbelief here, so it's a little bit tricky to try to convince everybody that this is really on somebody's menu.

Q: After all your research in this area, has anyone from the intelligence community ever contacted you, either admiringly or threateningly?

A: No. I have some other friends who troll the same sort of espionage porn that I do and dig around, and we always wonder if we're entering this number of search words all the time, what metrics are you entering into in some gathering site somewhere? I don't know. I don't think that's overly paranoid. But no one's ever contacted me.