When a murder shatters the quiet of a small town in the West of Ireland, Sergeant Gerry Boyle (Gleeson) begins to make connections with a local drug running ring. Teaming up with an American agent on loan from the FBI (Cheadle) he decides to take the law into this own hands as a gang of criminals descend on the town.

The Guard is the directorial debut of John Michael McDonagh, the brother of Martin McDonagh, who wrote and directed the Oscar nominated Six Shooter and In Bruges. The same vein of dark comedy runs through all three movies, with a satisfying dash of the absurd, but The Guard also carves its own niche as a home grown film which should have massive appeal both in Ireland and abroad.

Key to the success of The Guard is the towering central character of Boyle. He’s an enigma – smart and capable but prone to behaviour that borders on the criminal; whether it’s craving the attention of prostitutes or the odd class A substance. While his actions are often unusual, it’s to the credit of the screenplay that they never feel jarring, providing a carefully realised arc which comes to a satisfying, conclusion.

The narrative girth of Boyle leaves less room for the other characters, which are mostly sketched in hues of criminal or accomplice. Cheadle comes off as little more than a comic foil, reacting to Boyle’s seemingly innocuous racism and outlandish statements. Other names pepper the cast, including an on form Liam Cunningham, an underused Fionnula Flanagan and a wasted Mark Strong. With the latter’s commanding on screen presence, he doesn’t deserve to be relegated to a mere henchman position which could have been filled with any token character actor.

A meagre story and some lacklustre supporting roles aren’t enough to hinder The Guard’s best feature – it’s actually funny. Boyle’s pronouncements are impeccably timed and brazenly offensive, with much of the dialogue packing a zing we’re unused to in local productions. The interrogation of the stock criminal characters with exaggerated eloquence is a little less effective but still charming and the finale ends with some decently lensed pyrotechnics.

It would all be for naught without the presence of Gleeson. The film is as much a character study as a country cop caper and he gives his all to the performance, turning quirks into vital components of one of the more vital heroes we’ve seen on screen this decade. He’s smart, capable and hilarious and lives by an unwritten code that wouldn’t be out of place in a classic Western. Gleeson himself seems to be having a whale of a time with the character and we would love to see Boyle make the transition to other films, perhaps crossing the Atlantic for the sequel?

The Guard lacks the fantastical lurid and comedic highs of In Bruges and can’t match the spectacle of golden era buddy cop movies but works brilliantly on its own terms, focussing instead on character, wordplay and some fish out of water scenarios that will raise a smile in the most cynical viewers. Gleeson is fantastic, the script is top notch and the supporting cast do solid work with their limited screen time. A more compelling story and a few more explosions during the finale might have improved matters still further, but as it is The Guard is set for comedy classic status when it hits cinemas here in July.