For nearly thirty years Martin McDonagh has occupied a unique and thrilling place among today's playwrights and filmmakers.  On the continuum of directors McDonagh stands somewhere between Quentin Tarantino and Alejandro G. Inarritu, his characters driven by grief, anger or sheer cussedness to appalling extremes of violence.  McDonagh's sense of humor resembles Tarantino's, but his sense of tragedy and loss is much closer to Inarritu's.  Sometimes the mayhem in McDonagh's films and plays ends in death, sometimes in a sort of reconciliation between characters.  What it never does is resolve anything.  McDonagh's protagonists are left in the ruins of their lives, choking on the smoke and ash, contemplating their options if they are lucky enough to have any and smart enough to recognize them.  With infrequent exceptions (In Bruges, Three Billboards Outside Ebbing, Missouri) McDonagh sets his stories in Ireland, especially on the West Coast, his ancestral home.  The West Coast of Ireland is the setting of his latest film, The Banshees of Inisherin.  The premise of The Banshees of Inisherin is simple and odd in an almost Shakespearian way: a man living on the island of Inisherin (Inishmore and Achill islands stand in for the fictional Inisherin) decides one day to stop talking to his best friend.  From that beginning, McDonagh creates a metaphor not only for the Irish Civil War (the movie is set in April 1923) but for recorded human history. Padraic Suilleabhain (Colin Farrell), a farmer living on Inisherin, is by all appearances a simple man.  He spends his days lackadaisically tending his small dairy herd, knocking off at 2 p.m. to have a pint with his pal Colm Doherty (Brendan Gleeson).  His only real passion is for his beloved miniature donkey Jenny, which he treats like a pet dog and allows in the house to the displeasure of his sister Siobhan (Kerry Condon).  Padraic, known among his neighbors as a "nice guy," gets along with everyone, with a few exceptions.  One is Constable Kearney (Gary Lydon), the island's sole policeman, whose hobbies are getting drunk and beating up his eccentric son Dominic (Barry Keoghan).  Another is Mrs. McCormick (Sheila Flitton), a morbid local widow whom both Padraic and Siobhan hide behind walls to avoid. One afternoon Padraic knocks on Colm's door, as always, to invite him to the pub.  The interior of Colm's cottage—containing Colm's fiddle, his collection of masks, his phonograph and his John McCormack records—is very different from Padraic's, which has no distinguishing features except for Siobhan's books, which Padraic never reads. To Padraic's surprise, Colm ignores his knock and stares straight ahead, puffing a cigarette.  Padraic heads for the pub, expecting Colm to come along any minute.  Eventually Colm does, but he sits ostentatiously away from Padraic.  When Padraic asks him why, Colm's answer is blunt: "I just don't like you no more." Padraic, understandably, is nonplussed.  "You liked me yesterday!" he says.  "I thought you did."  Thinking that Colm is making an April Fool's joke, Padraic continues to seek him out, only to be rebuffed more strongly each time until finally Colm makes a dire threat. Without revealing its nature, Colm's threat and its consequences turn the story on its ear, to an extent some viewers will find difficult to accept. Suffice it to say that while The Banshees of Inisherin is less graphic than either In Bruges or Three Billboards, it feels more brutal than either. The characters, their community and their time help explain why The Banshees of Inisherin is more shocking than McDonagh's previous films.    Like Ebbing, Missouri, Inisherin is an isolated place, surrounded by great natural beauty (Ben Davis' cinematography is glorious), where the residents know each other all too well.  The people of Inisherin are expected to conform to certain patterns of conduct, and there are several enforcers, of whom Constable Kearney is only one.  The local priest (David Pearse) gets so enraged at his parishioners that he sometimes chases them out of the confessional, especially Colm.  Mrs. O'Riordan (Brid Ni Neachtain), the local store owner, judges all her neighbors by the quality and quantity of the gossip they provide; her favorite by far is Constable Kearney, and she shares his disdain for both Padraic and Siobhan.  The most alarming of the enforcers is Mrs. McCormick, who loves to present herself as the island's equivalent of the Grim Reaper.  Presenting herself to Padraic at one point, she predicts there will soon be a death on Inisherin, perhaps two.  When Padraic upbraids her for not being nice ("nice" is a word repeated often in the script, with increasing emphasis), she replies, "I wasn't trying to be nice.  I was trying to be accurate." The Irish Civil War, for the people of Inisherin, is nothing more than an occasional explosion on the mainland.  The only resident who expresses an opinion about it is Constable Kearney, who is delighted to have been asked to preside over an execution and excited at the prospect of watching people die.  "The Free State lads are killing a couple of IRA lads—or is it the other way round?" he says. In this intolerant community, Colm, Siobhan and Dominic are the odd ones out, as is Padraic if only by association.  Colm is outwardly the most complicated of the four.  A fiddler and composer so renowned that he draws music students from all over Ireland, Colm has decided to spend his last days on earth in the uninterrupted contemplation of life and music.  He wants to avoid all distractions, of which he regards Padraic as the worst.  The puppylike Padraic cannot accept this, even when Colm tells him outright that he's dull. "Yesterday you spent two hours talking about the things you found in your little donkey's shite!" Colm says. "It was me pony's shite!" Padraic answers.  "That shows how much you were listening!" As Colm continues to resist Padraic's entreaties, Padraic becomes increasingly less dull, and not in good ways.  At first he resorts to childish stratagems to remove obstacles between him and Colm.  Later, after a tragedy occurs, Padraic becomes Colm's implacable enemy, their relationship mirroring the violence occurring only a few miles across the water. This is disillusioning to Dominic, who regarded Padraic as his only friend on Inisherin.  "You used to be nice!" he tells Padraic.  "And now you're just like the rest!"  Dominic has an unrequited love for Siobhan, who is the island's sole voice of reason.  She is exasperated equally by her brother's childishness and Colm's obstinacy. "All I want is a bit of peace!" Colm tells Siobhan.  "You can understand that, can't you?" "It's an island, Colm," she answers.  "We've already got peace!" The Banshees of Inisherin is McDonagh's masterpiece to date, a rich, multilayered creation that demands and rewards extended analysis and contemplation.  Besides the magnificent photography, there is a notable music score by Carter Burwell, a musical question mark underscoring Padraic's bewilderment.  (The movie's traditional Irish music is also fine, much of it provided by Gleeson, an expert fiddler in real life.)  Above all, McDonagh chose the right cast.  The Banshees of Inisherin reunites Farrell and Gleeson, the stars of In Bruges, and seldom have two actors been so ideally cast.  Gleeson's performance virtually defines the concept of world-weariness, and Farrell is endlessly fascinating as he takes Padraic from simple contentment to confusion to rage.  Condon and Keoghan are also notable in performances that should raise their international profiles considerably. The Banshees of Inisherin ends on a suitably enigmatic note.  Mrs. McCormick sits in a rocking chair watching Padraic and Colm on the beach, smiling as Padraic declares his undying enmity to Colm.  "Some things there's no moving on from, and I think that's a good thing!" he says.  But the last two words in the movie leave us wondering: are they meant to be ironic, or do they offer the faintest spark of hope?  This is only one of the mysteries with which the film leaves us, and this is why The Banshees of Inisherin is a film that will last.