Last year, for the first time since the franchise began, a “Saw” feature failed to own the box office on Halloween. “Saw 6” was one of the best films in the series, a deft thriller whose ample gore was matched by slick directorial style and a witty, clever script — but not enough to match viral juggernaut “Paranormal Activity,” which trumped it on opening weekend and sent director (and series editor) Kevin Greutert packing.

But when Greutert got the call to helm “Paranormal Activity 2,” a convenient contractual loophole brought him back to film “Saw 3D,” the seventh (and supposedly final) series entry opening this weekend.

“This has been a hard year,” admits Greutert. “But at the end of the day, I didn’t want to let the fans down. I think we really made a film that continues the story but stands alone. I’m ultimately proud of this one.”

“Saw 3D” continues and climaxes the ongoing story of long-dead anti-serial killer Jigsaw (Tobin Bell) whose disciples continue to use devious, flesh-ripping death traps to teach sinners lessons that are often painful and fatal. And all of this mayhem literally jumps off the screen in digital 3-D.

“Needless to say, there are plenty of ‘comin’ at ya’ moments,” says Greutert. “There’s also tons of blood. We have an obligation to the hard-core horror fans to do that. It looks pretty damn great in 3-D, I must say.”