The plan going in was to gather resources for Feather Falling and better armor. That plan lasts about a minute. A new sign has turned up on the recovery chest at Iron Island, and what's inside means Basket can skip straight to work: finishing the sanding, then pulling all that sand back out.
Boots in the chest
The sign above the chest reads "Boots in here for Basket from JJ." Inside is a pair of Diamond Boots with Feather Falling III, Depth Strider III, Unbreaking III, Mending and Projectile Protection IV. "Okay, great. So we don't, we can just go right into it." Basket grabs more Water Breathing potions, since there's still no helmet for that, loads up on sand and heads back down to where the last session stopped.
Finishing the water
It's the same routine as before: wall off a pocket with sand, fill it, move on. This time there's an end in sight. "Oh, we're almost there. We can finish off the water today." More of it is already sanded than Basket expected, and the response is a simple "I appreciate it." The sand keeps running out, and the trip back to the chests is long, so Basket makes a shortcut: "I got tired of running all the way around so I made an entrance on the other side." When the nearby chest comes up empty it's a trip to the top for more, and the new boots get their first test on the way back down.
Pulling up the path
With the water gone, the dirt path that ran through the farm isn't needed anymore. Basket checks that nothing has to be loaded into the sorter from down there, then starts breaking it up from one end. A couple of mobs wander around on the floor far below. "I don't have a bow yet. I'll ignore him for now." Somewhere along the path Basket slips: "Oh, okay, I screwed up." The landing is fine, and Basket is quick to thank the boots for it.
Torches under the sand
Now the sand itself has to go. Basket cuts a hole for dropping things into, so "all the sand will go into the sorting system," then sets torches across the floor and breaks the sand above them. It falls onto the torches and pops into items. "I like how sand falls like that, that's pretty cool." One stubborn column of water turns up partway through ("Oh, you pesky, pesky water you"), and it gets plugged.
Clearing toward the mob farm
Next Basket starts on a whole chunk running over toward a mob farm, digging along a line first so as not to cut into the wrong spot. The idea is to keep a solid layer underneath so no gravel falls into the bottom area. At one point Basket wanders out of range of the beacons and loses the buffs. That leads to a thought about adding a fourth beacon so they sit symmetrically and cover the whole base.
What comes next
Asked whether the other directions will get stairs too, Basket says yes. The whole build is meant to be symmetrical: two sets of stairs on each side of the platform, a platform that will be obsidian once it's mined, and a rail on the inside so nobody walks into the drop. The next step is taking the whole cylinder down to bedrock. After that, either the gaps get filled in or Basket digs out even more so the iron golem farms show from below. The video ends on the credits with no gameplay after them.