"My wife gave birth to our second child 16 days before shooting, so I left her six days after my son was born. I'd been waiting 15 years for this and my life was on the line to a certain extent. So I couldn't give a crap and the cast picked up on that immediately. They realised all this guy cared about was trying to make the movie."
Margin Call is a ticking-clock drama that, according to experts, does add up.
It's set in a New York investment bank where Jeremy Irons' John Tuld is the chief executive (and is clearly based on Lehman Brothers boss Richard Fuld).
When Stanley Tucci's senior risk analyst is given his marching orders along with hundreds of other employees, he alerts Quinto's young analyst Peter Sullivan to the vast quantity of toxic assets that could bring the company down.
So the imperious Tuld flies in on the company chopper and calls all the troops to muster. Baker's Jared Cohen is in the upper echelons of management as a division head while Spacey's Sam Rogers is in control of the factory floor. Spacey delivers his trademark surliness in a role that fits him like a glove.
"Kevin visited a couple of trading floors and met the guys," Chandor recalls. "He could have phoned this in and it would have been great, but he didn't. He gained 20 pounds and found an amazing wigmaker - there are some bad wigs in the world and Kevin has worn one or two before, I think he'd even admit that," Chandor chuckles. "He transformed and looks much older. He would walk out with a limp, looking freaking exhausted. He was incredible."
Irons says he barely understood the 2008 financial collapse, "and I still don't really", though he read a book about it in the days before he shot his scenes.
These were done fast - a planned week of filming was condensed into three days after Irons realised his US visa was running out. Still he almost manages to steal the movie.
Chandor : "Jeremy came in with all those speeches down, these unbelievably intricate scenes. As a classically trained actor he wanted to nail them."
Quinto, who got his start in the sci-fi world of as Spock in Star Trek and Sylar on television's Heroes was also one of the film's producers and relied on Chandor's knowledge of the financial world.
"J.C. opened up an abyss of information that is still far beyond my mental capacity," Quinto concedes with Spock-like precision.
One thing he does know is that no one could stop the financial crisis.
Yet the interesting thing about Margin Call, he says, is there is no real bad guy. "The film allows the audience to draw their own conclusions. It gives them a certain credit and responsibility. I feel like it doesn't take the audience for granted."
Lowdown
What: Margin Call, global financial crisis thriller directed by J.C. Chandor
Who: Stars Kevin Kevin Spacey, Simon Baker, Jeremy Irons, Demi Moore and Zachary Quinto
When: Opens Thursday
-TimeOut