Basket did some work off camera before this stream: hoppers behind the storage room, a new set of stairs, chests in place. A few minutes in, most of it is on the way out again. The plan for Iron Island grows bigger the longer Basket looks at it.
A slow pickaxe and a new plan
The first problem is that digging is strangely slow. Basket had covered up the beacon by accident, and once it's uncovered the Haste comes back.
The stairs built off camera go down one side and soon run into the wall, with the ocean not far past it. So Basket rethinks the whole thing. It should be symmetrical: two paths climbing on either side and one path going down the middle. The top of the island won't keep its old shape anymore. It will step down "kind of like a pyramid," flat on top, with nether portals in the middle, and it's "all gonna be iron," which means waiting on the iron farm to finish it.
Tearing it out
The chests from the day before come out, then the hoppers and furnaces. Basket keeps the renamed "non stacking blocks," because renaming them all again is a pain. "So this project just got bigger, which is kind of how things work."
Breaking blocks over the open pit means they drop a long way down, so Basket pours water and lays a rough floor underneath to catch some. The new path starts nine blocks out, with a three-block gap so a walkway can run all the way around and the chests can sit in an outer ring. Steps go up with sea lanterns along the sides, and Basket notices "some serious lag" from all the lighting updates.
Chasing dropped blocks
A trip down to collect dropped iron blocks goes badly. Basket gets stuck below ("Oh no, I'm really in trouble") and admits, "I don't know if this is worth it anymore." Basket keeps pointing out slimes, though, and works out that the slime chunk seems to sit over the farms, so the tops of those farms might become slime farms. Only one would actually work, "but symmetrically wise, I want to make them all the same."
No railings, and the ocean in the way
An inner ring path goes in, three wide, with sea lanterns and slabs and a straight drop beside it. When a viewer asks about the lights, Basket says they're for lighting and for the look, so the torches can eventually go. There won't be railings: "just don't, you know, walk off the edge."
Counting nine blocks out at the curve puts the turn past the edge of the island and under the water. "We're gonna have to make the island a lot bigger." Basket switches to a diamond shovel, digs out the sand and lets the ocean pour in, mining underwater ("I have a diving helmet") and grumbling about ghost blocks along the way.
A narrow way down
The last question is how anyone reaches the storage. Basket settles on a path that slopes down from the inner ring to a lower ring, where the chests will go. Basket builds it while standing in water, so a slip doesn't mean a long fall. The path is narrow ("I wouldn't take a horse here"), and Basket's advice for visitors is "don't even enter this base unless you have feather falling four boots on."
Before signing off, Basket sketches the next step. The item elevator will get bridges out in every direction, and only one of them will carry items down into the storage ring. The video ends on the credits, with no gameplay after them.