Back up: "The Other Guys"

Just as all singers want to be actors, and all actors want to be rock stars, all comedians want to be action heroes, and all action heroes want to be comedians. Adam McKay's The Other Guys, a throwback to the buddy comedies of the 1980s from the director of Anchorman, opens with superstar detectives Danson and Highsmith (Dwayne Johnson and Samuel L. Jackson) piloting their car into the side of a Manhattan tour bus whilst in hot pursuit of some unnamed ne'er-do-wells, then propelling said tour bus - and the villains' own chosen vehicle - into the atrium of a corporate HQ, somehow emerging from the resultant fireball intact, and to even greater acclaim than they were used to going in. When the pair's invincibility runs out in unexpected (and very amusing) fashion, the NYPD is obliged to turn to their colleagues, hardened desk jockeys more commonly to be found ploughing though paperwork than traffic.

Terry Holtz (Mark Wahlberg) was demoted to a desk job after shooting baseball star Derek Jeter in the leg, and has been itching to get back to active duty; Allen Gamble, another of Will Ferrell's weirdly-haired middle-aged misfits, is a transfer from forensic accounting with a investigative preference for minor scaffolding violations. The case that falls to them involves Sir David Ershon (Steve Coogan), a British businessman in town to speak to the American Society of Capitalists - and you instantly suspect this organisation is going to be providing Hollywood movies with stock villainy for the next five years. (The Other Guys' one overtly satirical jibe finds Ferrell assuring the head of the SEC he believes is "the best at this kind of investigation", before going on to mention a few exceptions: Enron, Lehman Brothers, Bernie Madoff...)

The subsequent affair encompasses many of the staples of the modern cop drama: the formative traumatic flashback (here, how Allen Gamble accidentally became a pimp during his college days), the Irish bar that also serves as a warriors' retreat (here, the patrons sing comically anti-English ditties), the obligatory handing over of gun and badge, the good-cop-bad-cop routine that here cues another of Ferrell's large-scale freakouts. None of these tropes urgently needed debunking, you have to say, and even if they did, there's no great urgency in the direction, McKay and Ferrell using the narrative framework as another opportunity - after their 2006 collaboration Talladega Nights - to film male one-upmanship and spectacular car crashes.

Certainly, The Other Guys does little to address the essential boysiness of the New American Comedy, although the roughhousing at least throws up the odd funny idea, like a brawl at a funeral conducted in whispers out of respect for the deceased, and it has one great, self-aware riff on the way schlubby guys tend up to end up with smoking-hot broads in these kinds of comedies, McKay simply training the camera on Wahlberg's incredulous face upon the revelation Ferrell is shacked up with none other than Eva Mendes. It's yet another sign of renewed confidence within mainstream comedy that everyone from The Rock on down (or up) wants to get on the bus: it's good to see Michael Keaton back to something like his quirky best as the department's beleaguered captain, and one casual cutaway cues the best unexpected, blink-and-you'll-miss-it Rosie Perez cameo since that Little Jackie video.

Ferrell remains an acquired taste - there was, one concludes, some basis for that recent survey that suggested the actor provided the least value-for-money of any major A-list performer, not least as his high-strung mania proves most effective in small, carefully prescribed doses - but his pairing with Wahlberg, effectively stretching his cherishable grumpy-cop routine from The Departed to feature length, generates more sparks and felicities than his previous, rather noisy and self-cancelling duels with John C. Reilly. As is the manner of these things, having spent an hour having fun at the expense of genre conventions, The Other Guys eventually turns into a medium-octane exploding-helicopter movie in the broadest quotation marks, with jokes looped in as afterthoughts, and a closing voiceover that doesn't even attempt to resolve the glaring plotholes left behind (and appears to let the chief villainess - played by an actress who really should know better - off the hook entirely), but it's done with just enough brio to put the silliness over.

The Other Guys opens nationwide from Friday.