Duplicants keep collapsing from low oxygen until the game explains that a downed duplicant needs an assigned Medical Cot or Rejuvenator, and chlorine turns up.
With power almost gone, Basket wires pumps to wheel generators and turns off what the colony can spare, but food runs out and JJBonsig starves to death.
Basket hunts for the angle that shows the answer to a panel hanging over the water in the dark hall, solves it and the panel its cable leads to, and reaches a sunlit one.
Basket lights up a grid in the basement floor, finds the answers to a room of hexagon panels in the water below them, then heads down into a dark hall of blue panels.
With 14 stressed duplicants and the power giving out, Basket gets massage tables, unblocked toilets and a natural gas generator going, then sends carbon dioxide to the scrubbers.
Basket crosses into the desert, works out hexagon panels with the help of the sun's glare, powers three panels on a tower, and goes down into a dark room of red panels.
Basket lets the steam geyser vent, turns on a Fertilizer Maker for natural gas, plans a Natural Gas Generator, and fights stress and spreading polluted water.
Basket goes back to old panels that give no error marks, then clears walk-on floor puzzles in the sandstone ruins for what the commentary calls extra credit.
With 13 duplicants and not enough power to go around, Basket rebuilds pipes, adds a second water pump and a liquid filter, and digs toward the steam geyser.
Basket finishes a row of subtracting-shape panels, steps out onto the red side of the marsh, fires a light beam toward the mountain, then takes a long boat tour of the island.
Basket spends most of the episode on one panel with a two-by-two negation shape, cracks it, solves a checkerboard panel, and follows a line into a red room.
Basket finishes the marsh block-shape panels, meets a new symbol that subtracts shapes, turns a bridge with a square panel, and solves two more of the new panels underwater.