Episode 44 of The Witness opens on the big blue floor puzzle where Episode 43 stopped, and about nine minutes go to finishing it. Past it is a dark room with a statue, then two panels on a wooden wall that keep changing, and then a cave of pillars with panels wrapped around them. The video ends right after a pillar panel with suns is solved.
Finishing the big floor
The commentary sums it up: "It's a big huge puzzle on the floor, which actually has mirrored stuff," so a line drawn on one side is drawn on the other too. The small floor panels around it are "four mini puzzles that then create the requirements for the bigger puzzle." Basket walks between them and redraws them, since some answers can be turned: "we can change the orientation of this answer."
The plan that works leaves "a 2x4 where one of these two blocks isn't going to be filled in." At about 9:35 the line goes across the floor. "Yes! So good."
The figure in the dark room
"This looks like the end," the commentary says, then decides it is "another door." Through it is a dark room with red curtains and a pale statue of a figure sitting with a panel under a hanging lamp, small pieces scattered around it. "They're making the puzzles. This is all the negation blocks and the stars and the Tetris things." The commentary calls it "a potato person."
Two panels against the clock
Near a red mat on the floor are two panels on a wooden wall. "I found a thing, I'm stepping on it." Then: "Is this a timed thing?" It is. The panels close behind wooden covers and come back with new symbols each time, and the commentary says "I'm gonna solve it without narrating" because "the music is really intense." The left one is solved first, at about 12:45, and it stays solved when a wrong line on the right closes that one. "I don't have to solve them both in that amount of time." The right panel goes in at about 13:34, and the wall opens.
Pillars in the water
Behind the wall, pale columns stand in water, and the panels are wrapped around pillars. "Oh, this is trippy. I do rotate around the thing as I draw." The first wants the suns grouped so "there aren't too many suns together," and it is solved after a few tries: "we've unlocked that one." A pillar of dots follows quickly. The last one mixes suns and dots, and it takes almost three minutes: "the finishing move has to be going through here."
Where it ends
The final line goes in and glows white. "Are the suns together? Yes, apparently. Good. Moving on." The view turns toward another pillar, and the picture fades to the end card.