An improvised Eugene O’Neill ensemble barfly riff wrapped in the construct of a seemingly fly-on-the-wall documentary about the last day at an off-Strip Las Vegas bar, “Bloody Nose, Empty Pockets” pushes the envelope of nonfiction filmmaking in an exciting, immersive, and transporting way. The frame of the movie is intentional, the supposed regulars are the result of a casting process, the dialogue improvised, and it was primarily shot in New Orleans. But Bill and Turner Ross (“Western,” “Contemporary Color“) make virtues out of those concessions to dramatization and skillfully tease out some truths about improvised communities as well as the highlights and limitations of such alcohol-fueled connections.

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The movie’s structure is simple on the surface: just a couple camera operators hanging out during the closing of a bar called the Roaring ‘20s. Purportedly a Las Vegas cinderblock strip-mall boozer in the shadow of the Stratosphere, inside it’s the kind of local that everyone wants to have just down the block. The first-shift bartender gives everyone a hard time in that delicately friendship-signaling way and occasionally whips out a guitar for a quick serenade.

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The threat of gentrification is clearly messaged at the start of things, when a bartender declares he’s done with the new corporate Vegas, “Fucking Celine Dion can have it.” Somebody else chimes in that the bar will probably be turned into a CVS. That theme runs through the rest of the movie, though through more subtle suggestions. “Where’s he gonna go?” Somebody asks early on as Michael (Michael Martin), their resident barfly philosopher, groans awake and teeters into the bathroom to shave. It’s the mostly unspoken thought in the back of everyone’s mind that, come the morning, whatever camaraderie they found at 2am over a Jameson neat and underneath the twinkling Christmas lights cannot be reconstructed out there in the newer, colder Vegas.

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Inside the bar, the filmmakers skillfully weave together a cast that is just diverse and eye-catching enough to make for a well-balanced ensemble but without straining to give each of them a moment in the spotlight. The passage of time is occasionally signaled by the superimposition of a digital clock readout, and sometimes by the insert shots of the Vegas outside (rich with oversaturated color). But mostly the Ross’ track the day more subtly, through the TV (morning news turns to afternoon Jeopardy) and the steadily increasing number of patrons. Regulars come in and are hailed, songs are sung, disagreements spool up into fights and dissipate. All the while, Michael holds court, doling out advice—mostly about avoiding failure like him—with a gentlemanly courteousness, occasionally retiring to the back to read his volume of Frank O’Hara poetry and ponder the actor’s life he could have had.

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As the day wears into night and the night crashes into the after-hours late night where all the decisions are bad and all epiphanies fleeting, the tempo increases. A drag queen (Rikki Redd) friend of Michael’s puts on an impromptu show in fall sequins and makeup. A garbled soliloquy about the bar’s last day is mostly ignored. Apropos of nothing, a young musician tells his friend “I plan on doing some cocaine, too.” The late-shift bartender (Shay Walker) admonishes her teenage son, hanging around outside with his buddies, not to drink. An Aussie regular indicates that he took too much acid. At one point, everybody lights sparklers and heads out to the parking lot.

For the most part, the alchemy of spirits that make up a good bar are credibly and warmly captured. By underplaying most moments, and not pushing their performers to insert big look-at-me moments into the narrative, the movie can more often than not maintain the fiction that what we are watching is actually happening. The stitching of fiction into the narrative becomes more apparent when the filmmakers try to weave in the story of the bartender’s son and his two wastrel buddies. Whereas the action inside the bar is easily and organically constructed, the artificial construct is more noticeable by a camera just happening to be there when the teens are making their appearance, or oh-so-luckily catching the moment when one sneaks inside to steal a case of beer.

Nevertheless, by the time that the sun is up and Peggy Lee is singing “Is That All There Is?”, “Bloody Nose, Empty Pockets” has proven to be an impressively affecting and even slightly tragic piece about the homes away from home that provide comfort, as well as just how fleeting that comfort can feel in the bright light of day. [A-]

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