Episode 45 of The Witness stays in the room of pillars standing in water where Episode 44 stopped. Every panel here is wrapped around a column, so the line turns out of sight as it goes. One pillar of dots takes up most of the video. By the end it is solved, along with two others, and a mirrored pillar is left unsolved.
Black and white squares
The first pillar has black and white squares on it. "Separate out those dots," the commentary says, and the trick is the exit: "we kind of need to dip down through there." After a loop back to the start, the line goes up and out. "Yes! Awesome."
The pillar with three starts
The next one is much bigger: "we have lots of dots we have to cover, and then some broken spots. Oh, and like three different starting spots." The exit is "way over there." Every route hits the same wall: "we have to go both directions but we can't." Since the grid curves away around the column, "it's weird not being able to see the whole puzzle as you go." After about nine minutes of restarts the commentary admits "I think I'm stuck in the same thing I was stuck in last time" and goes to look at another pillar. On the way, a statue of a figure stands in the water: "Oh, there's a person over there. Hello."
Two shapes
The other pillar is friendlier. "There's no broken spots and there's two of those shapes," two small yellow block shapes near the top and bottom. The shapes look like they could trade places, "no I guess they'd share too much then," so they stay put, and the line goes in low, comes around and goes up. "I think I solved that one."
Back to the dots
Back at the big pillar, the commentary settles on one start and calls the line out a step at a time: "Here we have to go up. Here we have to go down." A dead end means backing up, and then the rest comes in one run: "up, over, up, down, over, up, exit, yes." The finished line glows white across the grid.
A spinning mirror
The last pillar has "the two suns up top" and black and white squares, with exits at the top and the bottom. "Oh, is this going to be a mirrored thing? ... A spinning mirrored puzzle." The plan is to "group the two white dots together" and cut off the black one. A few lines are tried, and none of them works. "I don't really know what's erroring either. Perhaps the suns."
Where it ends
The last try fails with two squares flashing red. "Okay, all right," and the picture fades to the end card with the mirrored pillar still unsolved.