Episode 43 of The Witness starts at the row of combined panels where Episode 42 stopped, five of them green and the sixth lit and waiting. One line clears all six in about two minutes. Most of the video then goes to two panels over a glass floor, whose lines are drawn onto the floor and get in each other's way. Once both work, an elevator goes down to a room of puzzles set into the floor, and a bigger one built from them is left for later.
Six at once
The sixth panel sits under black smudges on the wall. "I wasn't sure if there was, like, some extra thing to it, but I guess it's not." The commentary lists what the line needs: "We are crossing that spot. We are keeping that sun together," then a shape to fit in and a black dot at the bottom to fix. The line goes in, and all six panels glow green.
Two panels, one floor
Up the stairs, the commentary finds "the same puzzle we were looking at" over the glass floor, now next to a second panel with orange tiles. Each panel's line also appears on the floor as a wide path, and a new answer on one panel runs into the other's: "We can't intersect with the other thing's answer." The goal is a door that is not open yet. "I need to solve this one to be able to unlock that door, so both these two puzzles have to be solved."
Trading answers
For more than ten minutes Basket walks between the panels and the paths below, comparing gaps: "this one, there are two gaps on the far side, and then around this door there are gaps." One route lets a panel solve but blocks the other. Around the twelve-minute mark one is accepted, but "that didn't help me." The way through is to change each answer a little at a time: "as we sort of adjust each of the answers we can free up ourselves a little bit more." At about 16:30 it comes together: "And it's valid. Yay! Next room!"
Down to the floor puzzles
A small orange panel turns out to be "essentially just an elevator," and it goes down. "So now we're in the bottom of this room that we've been working on, doing all these crazy things, and there are puzzles on the floor." Looking up through the glass ceiling, colored lines show overhead. The floor puzzles use what the commentary calls negation objects: "that's valid because this one is wrong and we've negated it." Each solve lights up more of the floor.
Where it ends
After the last small puzzle, "now it's a meta-puzzle." On a wide blue floor, solving the small ones has "created shapes in the puzzles that I then have to add into the other one." The commentary calls it doable, "But not today," and the picture fades to the end card with the big floor untried.
