One cannot hear pans of a movie like those which greeted The Cobbler at its Toronto International Film Festival premiere in 2014 without becoming morbidly curious. Not pans. That's not a strong enough word. These were the hushed, strangled whispers of people who had seen something too traumatising to ignore, but also too traumatising to discuss openly. People did not walk out of The Cobbler like pissed-off movie critics; they walked out like combat veterans.

It's easy to assume that's just the usual effect of too much film festival intensifying everything; and even if it wasn't, there's a point where a film simply cannot live up to its reputation, either good or bad. And the opening 40 minutes or so of The Cobbler don't - they're mediocre in the most unentertainingly proficient way. Which is already an enormous disappointment, understand: this is the fourth film directed and (co-)written by Tom McCarthy, whose work has swung from the exquisite this-is-what-quirky-indies-going-right-looks-like The Station Agent, to the beautifully humane political fable Win Win. For The Cobbler to have been merely "fine", let alone outright mediocre, is already distressing to those of us who patiently wait for the distinctly non-prolific McCarthy (The Station Agent premiered all the way back at the 2003 Sundance Film Festival) to uncork another one of his quiet tales of life in New York anchored on a great character actor. And while I'd like to say that's the problem - The Cobbler eschews the likes of Peter Dinklage and Richard Jenkins for Adam Sandler - it's really not. One could not accuse Sandler of actively helping the film, but he's plainly giving the role and the movie just what they're asking of him.

The film opens with its best scene (though you wouldn't believe that at the time), exactly letting us know that we're in for a magical bedtime story that leans real hard on the kind of twinkly New York Judaism that would make Tevye the milkman groan at the corny stereotypes. It's more innuendo than actual exposition, and its meaning won't be fully explained until the last scene, but it does have the merit of introducing us to the generally dismal, "fuck you" quality to the proceedings from here on out, ending as it does with a dissolve that any first-year film student would tell you means that the little boy in one shot grows up to be the grizzled adult in the next, though it's also immediately apparent that since Adam Sandler isn't 110 years old, that's not what's going on. What is going on is that Max Simkin (Sandler) is a cobbler in a rundown ethnic neighborhood that's in that horrible trough where gentrification gave up, but it sucked away enough of the heart of the place that the locals don't have pride anymore. And Max is no more happy to be alive than any of the quiet souls who shuffle in and out of his... cobblery? I'm sure it has a real name. The point being, the film is jam-packed with mumbling lost souls who murmur lines in a dark haze, and Sandler's expression is never than a notch or two away from "gun in the mouth". At which point I will mention that the film believes itself to be a comedy.

Max discovers quite by accident that he has an enchanted sole-stitching machine: when he wears the shoes he fixes, he takes on the appearance of their owner (and smell, as we learn when he puts on a dead man's shoes). This opens the door to a lengthy chain of moments in which Max, literally walking a mile in other peoples' shoes, learns to appreciate their lives more, and tries to use his new insight to fix their souls, with a tedious awareness of the pun on soles. Having opened that door, The Cobbler races on by to find an even worse one, in which Max almost has sex with a woman while disguised as her British boyfriend, is delighted to find himself a Chinese man with a full-on Engrish accent, and is appalled to learn first-hand that some trans women can still have penises; all of these colorful roles played by game bit actors trying their best to play Sandler playing a sad-sack. It's generally a typical doofusy Sandler comedy, with the stereotyping and the everything-phobia and the unspeakably broken attitude about women. And through all of it, McCarthy directs and Sandler acts in that same funereal register. It's like Click as helmed by Robert Bresson.

All of this sucks, but in a mostly harmless, sleepy way. It's a film to ignore, not a film to hate. And then, a little before halfway through, the film rips off its mask to reveal the pustular zombified supervillain it has been all along. Max, you see, has noted that his mother (Lynn Cohen) has been sad. As well she might be, being a character in The Cobbler. But he has just the thing to perk her up: his dad's shoes have been lying around ever since he left ages ago. And before you can say "ohmygodno, ohmygodno, ohmygodno", zap! Max has taken the form of his dad, portrayed by Dustin motherfucking Hoffman, and he takes his mom out on a sweet, romantic date. Thankfully, she immediately dies before expecting her long-lost husband to return to the marital bed, but the damage has been done. And from the smoldering ruins of decent humanity that this scene has left behind, begins the bleak spectacle of The Cobbler: The Second Half.

Deciding that what his dead mom would really want is for somebody to stop the mad developers from destroying what's left of the fabric of the neighborhood, Max turns himself into a gifted con artist and superhero through the power of his magic shoes, first by scuttling the plans of local thug Leon Ludlow (Method Man, who does the best job of playing Sad Sandler of all the actors called upon to do so), and then, after he kills Leon by driving a six-inch plastic stiletto heel through his jugular - the film still thinks it's a comedy - going after the platinum-blonde psycho pulling Leon's strings, Elaine Greenawalt (Ellen Barkin). And for this he calls upon the help of peppy liberal activist Carmen Herrara (Melonie Diaz, giving the film's solitary performance that even flirts with words like "nuance" or "depth), and his buddy and neighbor, barber Jimmy (Steve Buscemi, a Sandler movie regular, so his presence isn't quite as mind-shattering as Hoffman's). And when he ends her nefarious deeds, which takes immensely little effort and time, there are still over 15 minutes of movie left, which leaves McCarthy and co-writer Paul Sado just enough time left to pull out a left-field ending that I won't spoil, because I can't. For one thing, I don't know how to describe it without descending into an impenetrable word salad. For another, I doubt that you'd believe me. For a third, there's no describing its impact: it only makes "sense" if you have the full weight of the preceding film to call attention to how immensely psychotic it all is.

But oh, that impact is something magnificent. The first 40 minutes of The Cobbler are obnoxious, bigoted, and unfunny; and then it gets worse, as the second 40 minutes are an inscrutable heist movie with an overweening desire to Say Something despite being completely deranged, and absurdly amoral for something nominally about doing the right thing, all while hinging its plot on the idea that every man in New York has the same shoe size. And then it gets worse. The movie plunges down and down, until it ends at its very worst moment. If there was anything in the whole 99 minute farrago to suggest that Tom McCarthy knew what humor was, I would insistently grab onto it as a parody of contemporary popcorn movies, but everything about the staging wants it to be sweet and tender and true.

The Cobbler is a film that is terrible primarily because of its screenplay and its director's astounding mismanagement of tone; it's not incompetent filmmaking. Mott Hupfel's location photography is perfectly serviceable, always in focus with the tripod staying level and everything. Nobody in the cast is bad, though they are often good at bad things. John Debney's and Nick Urata's score is a hilariously contrived nightmare of fake klezmer music, insisting on the merry Jewishness of a film that has gone out of its way to insult every other identity group depicted onscreen, so why not the protagonist's, too? So it's not incompetent filmmaking, but it's pretty goddamn uninspiring and irritating. It's still better than the film deserves.

Here, then, is my concern: it's really hard to talk about The Cobbler without making it sound like a mesmerising, must-see trainwreck. And oh, it is mesmerising. But it is not must-see. I have been taking my bad movie inoculations for years, and that last 15 minutes still left me a gelatinous mass. Of course, I fully expect that some people reading this will immediately hunt the film down, and I wish to publicly and earnestly disavow any responsibility for their choices. To lead people to The Cobbler would be nothing short of a crime. Not as big a crime as having made the film in the first place, but a crime nonetheless.