S Craig Zahler takes a lot of pleasure in perversity. This much was evident from Bone Tomahawk, his take-no-prisoners 2015 debut in which Patrick Wilson assembles a mismatched bunch of old west types to pursue his kidnapped bride and stumbles instead on a cabal of barbaric, cave-dwelling cannibals. For the follow-up, Brawl in Cell Block 99, Zahler upgraded to Vince Vaughn, who stars as a jailed drug dealer who is blackmailed into committing horrific acts of violence in order to be put in a maximum security prison, where he’s instructed to kill a fellow inmate.

Both films have a lot in common: notably the mashing up of disparate genres, sudden and extreme gore, and an air of gravitas bordering on the funereal. They are also rather long, clocking in at 132 minutes each. And for his third feature, Zahler really doubles down: Dragged Across Concrete – another fantastic but never really explained mood title – comes in at a mighty two hours 34 minutes, this time featuring not one star but two, seeing the returning Vaughn paired up with an even-more granite-faced-than-usual Mel Gibson.

One might expect this, then, to be Zahler’s magnum opus; and yet, somewhat counter-intuitively, it might be his simplest story yet. This time, there are three men in a tight spot, the first being ex-con Henry Johns (Tory Kittles), who returns home to find his mother on heroin and on the game, neglecting his crippled brother. The other two are police partners Brett Ridgeman (Gibson) and Anthony Lurasetti (Vaughn), who make headline news when their uncivil arrest of a drug dealer is captured on a cameraphone.

The three stories take a while to collide; when the two cops are suspended without pay, Ridgeman is hit the hardest, living in a tough neighbourhood where his teenage daughter is regularly assaulted. Ridgeman’s MS-afflicted wife wants to move, but with a drop in income, and no realistic chance of a pay rise, Ridgeman feels backed into a corner. Instead of waiting it out, he visits an old underworld connection – played by the unflappably louche Udo Kier, fast becoming a Zahler regular – who alerts him to an imminent bank robbery. Figuring that’s the easiest way to get rich in a short space of time, Ridgeman calls Lurasetti and proposes a plan to intercept the contraband. In the meantime, Henry, with no work forthcoming, has been recruited by an old friend as the getaway driver in the very same plan.

It sounds like the parts of a tense heist thriller are being laid in place, but Zahler is in no hurry to get to the job itself, and takes many digressions along the way. Some of them work – like the story of a bank teller who shouldn’t be going to work that day – and others really don’t, like an extended back and forth between Vaughn and Gibson as they prepare for their stakeout. Both, though, are a perfect example of where Zahler sees himself – what he thinks is his “thing” – and while it is certainly a matter of taste, this fusion of deadpan sincerity with wiseass, Tarantino-savvy dialogue is pretty unique to him.

Such a glum Gibson fits well into Zahler’s vision, which is probably just as well, since, in Hollywood terms, he’s still paying penance, and the film is very much about a man fallen from grace (the “dragged across concrete” could easily be Ridgeman’s ruined reputation, after years on the beat). Vaughn has the patter down pat too – and yet there’s something that seems to be missing from this all-too-promising package. Zahler has a way with action, and the set pieces are inventive and nasty, with an unflinching eye for violence. Such style and confidence is impressive. But after three movies, his increasingly morose characters’ world-weariness is becoming wearying in itself; a little more light and shade here and there would easily take this cult director to the next level. That is, if he wants to go.