"Saw VI" writers Marcus Dunstan and Patrick Melton are confident they have a winning formula for the franchise's latest sequel, which opens in theaters, Friday.

Having scripted "Saw IV" and "Saw V," the writing duo behind "The Collector" and the "Feast" trilogy are getting their footing "on what the fans want; what makes a really good 'Saw' movie, so I think with our third, we have a good grasp on that," Melton said in an interview with ShockTillYouDrop.

"It comes down to the 'A' story," he explained. "Not necessarily what John's doing, or what Hoffman's doing or what Amanda's doing. It's that 'A' story that's going to pull everyone together, the emotional hook. So there's this new character and he's going to bring us through to the end. With six, we put effort into it with Kevin to get a really good 'A' story. It's Peter Outerbridge, as William, and he has a connection with John and you'll understand that early.

"You'll understand the journey he has to take. When a trap starts, there's a much more emotional connection and you'll be rooting for this guy a bit more than you have rooted for anyone in the past."

Mapping these developments through the 'Saw' sequels was a challenging project for both writers.

"Well, it started with a big red wall and an apartment Patrick used to live in," Dunstan said. "We'd cover it with post-its about everything we would have loved to have seen in the first three films and everything we'd love to see in the future. 'Saw IV' had four different representations of what it could have been based on the criteria of availability and what kind of sequel it could be. Part five was crucial because it eliminated some key characters and introduced a backbone to what was supposed to be the villain carrying the torch.

"Six, then, is a great proving ground for Costas Mandylor [Hoffman] to just own. And now that we see that John Kramer is the deranged version of the philosophical Punisher, and Amanda was a tweaked Punisher, Costas has proven to be the sadist. A sadist still motivated by the philosophy is tremendously creepy. This time he doesn't have the teacher, the leash, the competition. He'll take this town apart piece by piece until he makes it what he thinks is right. That's exciting."

Melton promises an end goal behind the mayhem is in sight too.

"There's a light at the end of the tunnel we're leaning towards from four to five to six," he said. "When six ends, it could be the last, even though we know it isn't now.

"When six ends, John's plan is clearly complete and this is how he intended it to end. But, something happens and that's the natural springboard."

And how with "Saw VII" expand on this springboard?

"Seven had to answer a lot of questions even in its concept," Dunstan explained. "If the film is going to be 3-D, why would you ever do a 'Saw' movie in 3-D? Once that question was answered, we came up with a way to terrorize the viewer no other film in 3-D can do. Not even the big guns. This is something specific this series can shock someone with and reinvigorate the series. While six offers a nice bit of closure it also kicks another door open. If you can see that this happened now 'x' can happen and that was great. The transition from closing out six and starting seven has been the most streamlined yet."

See more of Dunstan and Melton's interview at ShockTillYouDrop.com.