Corrosion goes down, floor after floor, and every bridge on the way has holes in it. The trouble is they have almost nothing left to fill them with.
Not fixing all the bridges anymore
The room widens out at the base of the ladder, and the floor is crawling with stuff, zombie villagers included. Blocks are already running short. They tend to find blocks in chests, but this one is potions.
So the bridge policy changes. I'm not fixing all the bridges anymore. Just remind me not to take your bridge. Don't take my bridge. That was me reminding you. One of them jumps the holes instead, because he's super cool. Then he runs out of torches, so there is a trade: polished granite and other blocks one way, torches the other.
The ladder down
A chest turns up a chestplate with projectile protection. A skeleton shoots one of them and seems to jump off the edge afterward. There is a creeper spawner, and a quick question about PAX West (it was good, a lot of fun). Then the ladder down to the next floor, in the far corner.
They can't just dig down, because there is obsidian between the floors, and further down it is bedrock. Somebody suggests growing dark oak trees through it. The plan they settle on is to make one ladder line down from where the first ladder already is, so if they die there is a single way back, and to fetch more ladder material between episodes.
Spiders and an enderman
The poisonous spiders are back, in places they already cleared. Someone runs with nothing in hand, makes a leather chestplate on the spot, and grabs food to eat on the run. Stupid spiders everywhere. Then the chat reads Scoti_Garbidis was slain by Enderman, and later an enderman ruins everything again.
They work out that every intersection here has poison spider spawners, and that whatever they triggered earlier knocked torches off of them. So those spawners get taken out one by one.
The emerald
Basket, out ahead on his own, finds the thing he was trying to get to: an emerald, in a green glass box in the floor. There is a sword with it, Smite III, Fire Aspect I and Unbreaking I. Then skeletons, a lot of them, and one over his head he never saw. He is on fire, low on hearts, and decides this was a terrible idea. He retreats a level to put the emerald somewhere safe.
Time for supplies
One of them gets knocked off a ledge by a zombie and somehow lives. A pickaxe is about to break. They have no blocks, no torches to spare, and wish for a quick rail back to base. So they call it a short episode and head back for supplies, to come back better equipped.
