Bent Hamer’s wonderfully droll “O’Horten” tracks the unusual nighttime adventures of a mild-mannered train conductor coming to terms with the banality of his existence. He visits his mother in an old folks’ home, stumbles upon a drunken diplomat spread-eagled on the street, and has a memorable meeting with a blindfolded motorist. Like his Nordic soul mate Aki Kaurismaki, Hamer sets up a series of atmospheric vignettes that speak to the absurdity of life with gentle, off-kilter humor. Odd’s life has been utterly predictable, but when he goes off the tracks on a quest for personal meaning, Hamer hits a note of high-flying grace.