Episodes 5 through 8 of Twin Peaks: The Return are shown tonight in a mini-marathon, bringing viewers up to speed on the Twin Peaks sequel. But the speed, to this point, has been about as deliberately and maddeningly slow as watching someone sweep a barroom floor in real time to the music of “Green Onions.” Which, I swear, was one scene in this new David Lynch-Mark Frost revival. But nothing was stranger, or more memorable and inscrutable, than Episode 8, which features a grizzled, threatening old man wandering around taking lives, reciting foreboding poetry, and asking, over and over, “Got a light?”