When Arnold Schwarzenegger made his brief uncredited cameo in 2010’s "The Expendables," it seemed to signal the former superstar’s return from political exile to his native, ass-kicking action movie habitat.

Four years later, the comeback hasn’t gone as planned.

"The Expendables 2," featuring an expanded Governator presence, grossed less than its predecessor. As he stepped further into the spotlight with true lead roles in last year’s "The Last Stand" and "Escape Plan," the results, quality wise, were lukewarm at best.

Meanwhile, at the box office, lukewarm would be considered an improvement. While his last two efforts played well abroad, domestically they stand alongside the failed Conan spin-off "Red Sonja" as the worst grossing films in his career (and generally speaking, it’s never a good thing to be mentioned in the same sentence as "Red Sonja").

Blame it on poor material (the old jokes have become exactly that). Blame it on his broken-down public image – or, perhaps worse yet for an action hero, his broken-down body. Blame it on the fact that he’s the face of a type of innocently dumb, sincerely mindless action movie that doesn’t play with today’s cynical, grittier tastes. The fact of the matter is the general public is telling Arnold to talk to the hand.

Instead of licking his wounds and safely heading back to familiar territory, however, "Sabotage" finds Schwarzenegger briefly pushing his persona in a new direction. It’s not simply that the film is unexpectedly more murder mystery than action thriller; "Sabotage" is easily the most unpleasant, most vulgar and most violent movie on Arnold’s resume. Credit where credit is due for trying something new, but considering the film’s startlingly mean, brainlessly scummy ugliness, it qualifies merely as a not-quite-noble failure.

Schwarzenegger plays Breacher, the rugged old leader of a rough-and-tumble DEA task force filled with corrupt psychopaths (including Sam Worthington, Terrence Howard, Josh Holloway, Joe Manganiello and a trying painfully hard Mireille Enos) with nicknames like Monster, Grinder, Pyro and … Neck? On an early mission, the team hides $10 million of drug money – in between plentiful splattery headshots – to claim for themselves. However, when they double back on the scene, the cash has gone missing.

One internal affairs investigation and suspension later, the group comes back together. Their happy, profane-tastic reunion is short-lived, however, as one by one team members are turning up brutally murdered. One is parked in front of a speeding train; another is killed, gutted and hung from the ceiling like a mobile designed by Hannibal Lector.

With his crew’s numbers dwindling down in gruesome "Ten Little Indians" fashion (the movie’s original title was fittingly "Ten," though there are only nine team members so … ), Breacher hooks up with Investigator Brentwood (Olivia Williams, sporting a sassy Southern drawl) to try to piece together the case. Based on the gory crime scenes, the clues point to some revenge-minded cartel the team busted in the past. As the bodies pile up, though, the remaining members start wondering if the killer is one of their own.

"Sabotage" lands right in the wheelhouse of director David Ayer, whose resume is almost exclusively filled with similar, mostly solid gritty procedural pulp cop dramas like "Training Day," "Street Kings" (I said mostly solid) and "End of Watch." Nobody would accuse Ayer of venturing too far out from his niche here, but he does have a flair for the genre. His action and visual approach has a slick grungy verve, and as with the rest of his work, there’s also a certain amount of researched authenticity to the minutia of the job. 

Unfortunately, he’s saddled with Skip Woods – the hack scribe behind shiny dreck like "Swordfish," "X-Men Origins: Wolverine" and the breathlessly stupid "Hitman" – as a co-writer. Worst yet, the script seems to bear Woods's mark – one that turned the beloved John McClane into a nagging, destructive sidekick in "A Good Day to Die Hard" – more than Ayer’s.

All of his signature elements are there, including witlessly crude and annoyingly unnecessary quipping – perfect for viewers who wanted more of McClane yelling "I’m on vacation" in "A Good Day to Die Hard," only more profane. For a "covert, undercover" team, they sure do obnoxiously blab a lot mid-mission about farts and other savory topics. They also seem to have learned their nuanced covert tactics from Arnold’s "Commando."

Ayer and his overqualified cast try to summon some chemistry out of the script’s blather. Williams and fellow detective Harold Perrineau fare the best. It’s difficult, however, when the dialogue is childishly vulgar, and there are no real characters to care about. It’s almost a guarantee, for instance, that you will forget Terrence Howard is in the film.

Meanwhile, Woods throws together a slapdash mess of plotlines – the missing money, the murder mystery, reassembling the team, plus a subplot about Breacher’s haunted memories of his wife and child, brutally tortured and killed by a Mexican cartel – that never coheres into a compelling story. The mystery winds up mystery-free, and when "Sabotage" finally gets around to trying to wrap it all together, it seems the killer’s final victim is the audience’s ability to buy this ridiculous nonsense.

Even before it reaches its final set of ludicrous twists – one requiring a character to pull a Batman-like disappearing act in broad daylight, surrounded by cops – "Sabotage" becomes too idiotic to be taken as anything approaching serious, while also too overwhelmingly grim and ugly to be entertaining or any fun. The misfire’s only real worth is as an oddly admirable anomaly for its aged star, though even hard-core Ahnold fans might be better off admiring it from a distance.