“Saw” was never designed to become a franchise. The first film made a point of killing off all its main characters, save for one who was already dying of an inoperable brain tumor. But when a movie grosses 100 times its budget, filmmakers tend to find untapped wells of ingenuity.

“Saw VI” tells a story that is almost certainly incomprehensible to those who have not seen the previous five films. The entire plot hinges on the reveal of an element first introduced in “Saw III,” and details the rise of a character that made his debut as a glorified extra. The entire twist of the film’s end is predicated upon the viewer’s memory of a secondary character that is never even onscreen during this feature, except during a brief flashback. Because of this, plot summary is useless. You either know what to expect, in which case it is best to see the movie completely cold, or you’ve already determined that you don’t care.

“Saw” has always worked under a strange moral code, espousing a bizarre brand of carpe diem philosophy uttered by serial killer who believes he is saving people by throwing them in pits of used hypodermic needles or forcing them to cut off their own feet. This philosophy has long been an albatross for the series, because Jigsaw’s ideas are — to put it bluntly — completely idiotic. The result of these “tests” would likely be a case of post-traumatic stress disorder, not a moment of revelation.

“Saw VI” makes it hard to solve this problem: For the first time in the history of the series, Jigsaw is revealed to be at least a bit mentally unsound. This is a small but important advancement for the filmmakers, as the series makes infinitely more sense if Jigsaw is taken as a David Berkowitz type, rather than some sort of blood-and-guts-loving Buddha. Simultaneous to this, the filmmakers have finally created a cast of victims who might very well deserve their fate. It’s actually quite surprising that it took five sequels to get to a trap where loan sharks are forced to contend with Shylock’s infamous demand for “a pound of flesh.”

While many have anticipated a jump to the supernatural for several entries, few (if any) guessed that “Saw” would ever become a political story. You see, “Saw VI” is just as much about the current healthcare reform debate as it is about soap opera-style plot twists. In one scene, Jigsaw literally states, “Medical decisions should be made by doctors and patients,” before going on to equate HMOs with murderous thugs. And while the political polemic elements are a bit overcooked, they do imply a level of effort on the part of the filmmakers that goes beyond the call of duty.

Longtime series editor Kevin Greutert moves to the director’s chair for this entry, and his experience with the franchise shines through. He has clearly been planning for this opportunity for quite some time, and he makes the most of it, combining the grunge aesthetic of the original with the flashy scene transitions of the sequels, all the while expanding the color palette, steadying the ADHD-afflicted cinematography and toning down the explicit violence series devotees have come to expect.

Everything that was wrong with the five previous films is still wrong here: The sets still look like those of a movie made for about a million dollars, the actors are still mostly second rate and the logic is still tenuous, within a real-world scenario. The dialogue is occasionally as cringe-inducing as the gory set pieces, and the film’s script makes excessive use of expository tape recordings in place of legitimate character development. And yet I had a damn good time.

This film is easily the best since part two, and somehow actually made me want to see part seven. For those already invested in the series, “Saw VI” is a Halloween treat. It’s smarter than the previous three films, and it features some of the series’ most interesting traps. It even gives you a little something to talk about after the credits roll. Most will hate it sight unseen, but to those who show up to watch, “Saw VI” is better than it has any right to be.