With his winter white muffler of whiskers, small, darting eyes, deeply carved, Nordic features and long, hanging limbs, Jørgen Lauersen Vig may be the documentary subject of the year on aesthetic grounds alone. Director Pernille Rose Grønkjaer really hit the jackpot, however, when the 82-year-old Dane, a lifelong bachelor/loner with the attendant oddities and peccadilloes, decided to fulfill a lifelong ambition and turn his brokedown castle into a monastery, and invited a group of stone cold Russian Orthodox nuns to give it a test run. The Monastery: Mr. Vig and the Nun, the slim, sparsely drawn and gently affecting documentary that resulted from the several years Grønkjaer spent at Vig's castle in the Danish countryside, fulfills the promise of Vig's singular visage.

Grønkjaer is also the sole photographer for The Monastery, recalling in technique (and a few other things, including the masterful use of natural light and a steady, hypnotic eye for the quotidian) the one-man crew of the other monastery documentary from earlier this year, Into Great Silence. Though she can be heard off screen occasionally, prodding the naturally withdrawn but hardly reticent Vig with questions, and steps into the frame once or twice when the old man requests her help, Grønkjaer's camera is a patient, sometimes wry, sometimes tense and tactful observer, recording the touching decline and reinvigoration of the castle, Vig and his mysterious guests with an equalizing curiosity.

The tone is set between Mr. Vig, who is shown diligently preparing for the descent of a small clutch of six Russian nuns, including their leader, Sister Ambrosija, when he leads them into their sleeping quarters and points at the existing furnishing. "It's called an opium bed," he says. "For smoking opium." I don't know if you've seen a Russian Orthodox nun lately, but they're not really Sister Act material; Ambrosija, a seriously and efficiently lovely woman with a similarly modified countenance, begins requesting changes almost as soon as she is through the door. Mr. Vig is amenable initially, but tries to warn her, "Everything goes slowly in our place. Slowly." The clashes between the two on the subject of renovations to make the castle livable make up much of the ensuing drama; the structure cannot hold, Ambrosija argues, not in the long run, and this gives Mr. Vig more to think about than he had imagined.

In between their increasingly bitter clashes, Mr. Vig and Grønkjaer repair to a corner of the castle, or some pocket of the grounds, to rehash the progress or lack thereof. The devastatingly ascetic schedule of his guests ("Nuns don't get tired," he tells a friend) stuns even the eighty-something Mr. Vig, still spry and active in the DIY restoration. The other nuns are distant, sleek figures, shrouded in habits and most often standing before icons or with their heads down, engaged in work if not prayer. There are moments of frustration and triumph, all of them sweetly minor, and an increasingly intimate investigation of Mr. Vig's self-contained past -- his father was the only person he ever cared for, and it seems possible that he is still a virgin. Listening to a man at the end of his life respond to a question about love with genuine bewilderment -- "It's just a word," he says -- will break your heart.

Mr. Vig's mortality and his desire to make something enduring was the reason for beginning the monastery endeavor, but he finds "enduring" to be a relative concept as Sister Ambrosija digs in for the long haul. The permanence of the proposed agreement (that Vig will the building to them) begins to sink in, and Mr. Vig is a divinely stubborn dichotomy, even in his ostensibly peaceful decline. Even after unleashing a massive bureaucratic bitchslap in which he refers to Sister Ambrosija as "an itinerant, tourist nun," she returns to Denmark and the monastery, offering solutions and compromise along with her other cheek. The remarkable scene in which the re-installed Ambrosija silently prepares and serves a meal for her cranky, would-be benefactor bears a level of tenderness so stubborn it almost matches his; it is a tribute not just to the director but to the relationship she documents with such grace.