Yet "Prisoners" doesn't lag at all at 153 minutes. "It is a slower-paced film than a lot of young people want to see," Cox continues. "But this is the type of film I tell students all the time: You could not do this in a chop, chop, chop, beat to the music way. Or this film would be nothing. The whole film is about the reality of what these people are thinking or feeling. And I think the picture ended up being just that."

However, the toughest scene for Roach was the torture of Dano. And they went back and forth from two to three punches, and actually locked picture with two punches, when the director decided to go with three the following day.

But because they were in the digital world and in the hands of master cinematographer and 10-time Oscar nominee Roger Deakins, Villeneuve could reset on one take four or five times until he got the exact performance and the right emotional look. That's not to say he didn't allow room for improvisation. For instance, Jackman amped up the rage in blowing up at Gyllenhaal when his daughter is first kidnapped, and later beats the dashboard when in the car with his co-star.

For Cox, the car ride was the most challenging scene, but made technically easier by shooting with a camera outside each of the two windows. "The great thing about the car scene [in which Jackman conceals a crucial plot point from Gyllenhaal] is that they have this discussion about life," Cox explains. "It's pretty much the way I cut it the first time -- they were riveted by the intensity of those two actors and why Jackman has a bottle and all that."

The way the two editors work is totally in tandem, where they stay close to camera and will even split a long scene in two (of which there were obviously many on "Prisoners"). Then they'll put it together with only slight adjustment based on notes because their styles are so similar. Cox has worked with Eastwood for 35 years (winning an Oscar for "Unforgiven") and Roach rose to co-editor on "Letters from Iwo Jima."

"We play it so we learn what the actors learn and today you're seeing films where the audience sees it before the characters do and you just can't do that," Roach insists. "I get annoyed with filmmaking like that."

Roach says it helps being a people watcher because then when he observes the performances he can formulate them into the memories he has of particular emotions. "You have to live those characters' lives."

It's the greatest lesson they've learned from Eastwood, who's all about capturing the actor's moment of discovery. "With Clint being an actor first, his goal is to get you that first time when your body language is not sure where you're going and you're vulnerable to something. And he says that is magic," Cox observes.

Meanwhile, Cox and Roach have resumed working with the 83-year-old Eastwood on "Jersey Boys," the adaptation of the Tony Award-winning musical about the rise and fall of The Four Seasons for release next year. They're not only "rhythming the dialogue" but also the songs to achieve Eastwood's sought after spontaneity.