Before Brendan Gleeson and director John Michael McDonagh teamed up for Calvary, they delivered a full, and funny, measure of testosterone and adrenaline that didn’t demand that you dial back your IQ to enjoy it.

The Guard just might be the most engaging, inventive, and satisfying buddy cop/fish-out-of-water/anti-authority/dramedy ever committed to celluloid. You might think that’s narrowcasting in the extreme, but we’ve seen a slew of them, going back to the ’70s, when Dennis Weaver starred in the made-for-TV movie series McCloud, up through the pairing of Jackie Chan and Chris Tucker in the Rush Hour franchise and beyond.

From its very first scene, The Guard tips its hand that it isn’t going to be your typical “Yippee ki-yay, motherfucker” kind of cop flick. Officer Gerry Boyle (Brendan Gleeson) is stationed on traffic patrol in Ireland’s beautiful hinterlands when a car blows past him at near-supersonic velocity. Before he can pull it over, a rather spectacular (and fatal) crash ensues, and a matter-of-fact Boyle surveys the damage.

Once he’s established Boyle as something of an off-kilter hayseed, writer/director John Michael McDonagh introduces FBI agent Wendell Everett, magnificently played by Don Cheadle. His job: to coordinate with the locals to intercept a half-billion-dollar drug shipment. On the face of it, Everett is everything Boyle is not: by-the-book, city-bred, buttoned-down, American . . . and black. While the racial dynamic is played for straight hilarity in so many of these buddy movies, director McDonagh milks the natural tension for some truly cringeworthy moments.

In some ways, the relationship mirrors the tensions between the old world and the new; while Everett embodies the hard-charging, can-do pragmatic American spirit, Boyle is significantly more laconic, even somewhat existential, in his approach to fighting crime. The mere idea of yoking a thoroughbred with a Clydesdale to the same cart—or case—is rife with comic possibilities, and they are by no means left unexplored. As one might hope, the rocky start between the two cops ultimately gives way to a grudgingly respectful rapport, though it’s not without its occasional zingers, as Boyle dodges expectations at every turn, keeping both Everett and the audience slightly off guard.

As for the trio of bad guy Brits that Cheadle and Gleason find themselves pitted against, well, they’re not your typical toughs, either. Sure, they’d just as happily blow a hole in your face as give you the time of day, but they’re also remarkably literate for thugs, even given to bouts of introspection about their line of work (though the classic scene illustrating this doesn’t seem to be available anywhere online, damn it). Assuming they can buy their way out of any prospective trouble, they try to bribe the local constabulary to look the other way, and it just about works.

From here on out, leaking any further plot details would be doing you a disservice, but suffice it to say that if The Guard had heretofore largely shunned the kind of bullet-spewing, explosion-laden set pieces that typify American cop films, it embraces them enthusiastically in the last reel. And we begin to see how the two disparate cops’ weltanschauungen has begun to invade one another’s psyches, with Boyle figuratively strapping on the six-gun and Everett turning inward to consider the consequences of his actions.

Hijinks ensue, but not before director McDonagh defies expectations (and convention) with a couple of plot wrinkles that are as bracing as they are unexpected. By the time the credits run, you’ve had full measure of testosterone and adrenaline without having had to dial your IQ back into the double digits.

To which I say, “Yippee ki-yay, motherfucker.”