Episode 5 of Hypermine Vanilla Season 1 goes back underground, to the secret base under Scoti's lawn. Basket shows off the redstone added since last time, chases down a beacon beam that will not come through, and builds a hidden entrance into Scoti's basement on camera. By the end, one button opens and closes the whole base, and a small cubby sits ready for brewing gear that does not exist yet.
The tour
Up top, the old dirt hut has been redesigned into what Basket calls "a fruit bowl/banana fish." The trapdoor entrance is still there.
Down at the bottom, a new button runs the room. Press it and the storage compartments open, the floor "kind of bubbles up" and drops again, and a staircase opens one step at a time. One spot opens so a beacon below can shine up, with a block swapper trading an iron block for glass. A trapped chest opens a side panel into the work area. Under the floor, "kind of a mess," a main T flip-flop drives it all.
An edge detector
The block swapper had a flaw. It only swapped once per cycle, and it needs to swap both when the line turns on and when it turns off. The fix is what Basket calls an "edge detector." A working one sits downstairs, and Basket rebuilds the idea up top: a dropper with a hopper feeding it a single item and a comparator reading it.
A hallway button, wired through an AND gate, only works when the room is already open. Then the test. It should be glass all the way up. "Maybe? Maybe not?" No beam. "So I'm concerned that something is broken."
Water in the way
The problem is higher up. Basket breaks through a wall, throws an ender pearl and ends up below a pool of water near the surface, using ladders to hold the water back. With a guess at where the hole lines up, one block comes out. "Oh, there we go. Yeah, the beacon's shining through." The water and a few torches get messed up on the way, and the torches go back roughly where they were.
The beacon gets new powers. Haste comes off, and after trying speed with regeneration, Basket settles on Speed II. "So now everybody can zoom around." The catch, as Basket points out: the beam only shows when the base is fully open, which won't be often.
A door into Scoti's basement
Scoti's basement turns out to be "fairly high up." Basket builds a small room off camera, then wires the door on camera: two sticky pistons, a redstone block and a torch on each side. The first try "didn't quite do what I want," and the wiring runs through a cramped space that needs temporary scaffolding.
Then the button does nothing. It is in the wrong spot, and moving it is the easy fix. "Yay, I can get into Scoti's base." A second press closes the wall again, and some of Scoti's dirt patches the hole. The leftover space will be a brewing cubby, small but "enough of a little cubby for that."
One more break
Back at the main room: "I broke something." A signal is looping back into itself. An extra repeater, a shorter delay on another, and one more block sort it out. A button with no sign yet becomes a reset switch. Then the full run. "Sequencing is good." Open, closed, open again. "I could put a little bit more of a delay on that maybe, but this will work."
Where it ends
The furnaces and chests are still scattered around the room, and next episode is "a different project." The video closes on a short shot of a player in diamond armor standing in the open room, the beam running up beside the player, with no end cards.