Part 3 starts right where Part 2 stopped, next to the spawner for the big mob in the lava. Nobody has killed it yet, and they agree to leave the spawner alone in case it drops something important. The party is still johnfal_92 and Dash (dash10138), going by the nameplates and chat. Scoti isn't on.
Up the ladder, into the creepers
The first trap goes off almost at once. Then there's a ladder going up, and the sound of skeletons and creepers above it. Dash and John climb. Two lines show up in chat at the same moment: Dash was blown up by Creeper, and johnfal_92 was blown up by Creeper. "Oh wait, did you both blow up, or just one of you?" Both. As one of them put it later, "going up a ladder into a creeper room I guess didn't really work out."
Picking up the pieces
Basket stays down where the others died and works on recovering their things. "Yeah I'm right where you died. I've been trying to recover stuff." What fits goes into a chest that becomes the death chest. The creepers keep spawning, so somebody lights up the room to slow them down. The two chests they died for are up through a wall they dug into, and they grab everything and break the chests. "Oops, I just grabbed the trees. Don't need trees. Or uncooked rabbit." Space is tight. One of them has a stack of ladders and no idea why.
Is it trapped?
On the way back they slow down and check chests before opening them. One of them explains the trick: press F3, look at the block behind the chest, and see if it's gravel. One chest turns out to be lit by redstone but harmless. Another really is a trap chest, but all it does is release poison, so it's fine to open. Somebody finds extinguishers, which "seem important" in a dungeon full of fire. Then it's Dash's turn to save someone. One of them walked under a creeper drop trap, and Dash blocked the hole above in time. "Thank you, Dash, for saving our lives."
A patch of gravel in a wall turns out to hide a secret chest. They decide to come back for it, and for a few others, with luck helmets on. There's also a talk about the weekend. If one of them can't play, the others could clear it and come back later just for the wool. One of them would rather have it all on video, though.
Blazes and falling creepers
The next room has a chest in the middle with a spawner under it, lava below and above, and blazes. One of them pulls out a "super bow" for the blazes. Creepers keep falling through holes in the ceiling, so they close the holes up. "We will hear creepers falling but they are in theory neutralized."
Jaguar Spirits
Then a mob shows up behind them, and then a lot of them. "They hit really hard." Chat reads that Dash was slain by Jaguar Spirit. A spawner above the room has been dropping them down. One of them falls back to eat while another goes up to break both spawners there, trying not to walk over Dash's dropped gear so nobody has to sort out inventories later. A sign near the spawners says, "Through time all falls into ruin." Nobody knows what it means yet.
They push on into a room with skeletons on the left and more spawners, and mark one more double chest as trapped, with gravel behind it, for later. The episode ends at the bottom of a staircase with a creeper spawner up top, and one of them realizing they haven't been using their wand.