The biggest thrills of the Saw movies are their surprise endings, which seem to keep audiences guessing even more than M. Night Shyamalan's latest creations. That's why the producers of the Saw sequels are starting there and working backwards.

"We just basically locked down the ending about a month ago so it's working off of what happens from there," said Oren Koules. "There's nothing guaranteed. It's really Mark [Burg] and I looking at each other and saying, 'Okay, this story works, let's go.' When it doesn't, we won't go. We'll miss a year, we'll miss two years. It's two things: If we have a story that works and the fans want to see it. It's such a simple equation. Right now we're working on some things on V. There's nothing definitive."

Burg may even have plans to make Saw V and VI at the same time, though coming up with two shocking, surprising scripts for one epic shoot may not be possible (especially now with the WGA in full effect). This plan also hinted at which characters from Saw IV might become the focus of a Saw V.

"It was an idea of ours to try and keep the cast together because it's really difficult with Scott [Patterson] doing a TV series and other people doing other shows that we're going to try to. I'd say it's not out of the question but it's going to be really hard for us to get the screenplay to Saw VI where we want it to be to be able to do it."

If Saw V does go ahead, it looks like Jigsaw will remain a factor. Despite having his head on a morgue scale on the posters for Saw IV, Koules wants actor Tobin Bell back for "as many as he wants."

The boys know that they won't always be making a Saw movie a year. They're prepared to accept their fate when the grosses go down. "I think we'll all know," said Koules. "As of the tracking, as of today and as of everything else right now, we're still rolling. Listen, we're surprised. There's going to be a day we wake up, we don't have a $25 million weekend, we have a $4 million weekend. We're fine. We own the films. We're okay."