Episode 23 of The Witness picks up in the basement where Episode 22 stopped, beside a red grid set into the floor. Basket works the grid out by moving the light, goes down to a pink stone room where the answers to the panels show up in the water, and ends the video in a dark hall full of blue panels, most of them still to do.
The grid in the floor
The room holds a small blue screen on a stand, two red panels with orange zigzags, and the red three-by-three grid in the floor. "Okay, more lights." A wrong guess costs nothing ("if I get it wrong, it doesn't reset it"), but guessing is hard "because there's a bunch of starting spots."
Basket climbs out to the desert and looks down over the ruins from up high, trying "to see if any of these symbols mean anything." Back below, the screen gets turned again ("Can we just move the light?") and the answer comes together in pieces: "So that, and then that little L." After a few tries the whole grid glows orange. "We were missing some of it, but okay, progress."
Answers in the water
Stairs lead down to a pink stone room with pools and hexagon panels on posts, and no sunlight: "more puzzles, just water." Then: "Do you see what I see? It's in the water." A shape with a line on it shows in the pool under a panel. "This is a lot easier than trying to get the sun to work. But it's a reflection, so we need to keep it in mind."
The panels go one after another. "Oh, it's actually exiting through the bottom. Awesome." Some reflections are harder to read ("We can't even see as much, so that makes it tougher"). Orange round shapes with a wedge cut out stand near some panels, and the commentary calls them Pac-Men. One more panel, then: "Yes!"
Down to the dark hall
Past a green lever by an orange door, stairs lead down into a dark hall of wooden walkways and scaffolding, with blue hexagon panels on the pillars. "It's draining the water. Is that what we want?" Then: "Goodbye, water." A lit passage at one side ends at a gate: "Oh, I've been here before."
The blue panels bring "a new gimmick." The commentary decides "there's something important with the water," then "when the water is down," and tries one: "I guess I can just solve it right now." A blue cable lights up and runs across the floor to the next panel.
Where it ends
Another panel "we potentially need the water to be up to do." The plan: "we still need to maybe drain the water and then get the right spot." Basket walks the walkways, the view stops on a long blue panel up close, and the video fades to the end card.