I had a dream that the new DF version was released, then I played it. I did the usual digging-down-to-caverns start except I was intercepted on the way by what looked like blood red naturally generated smooth halls. Kind of like HFS, but not slade. So then it was diggable and I kept telling the dwarves to dig stairs down until i came to a relatively large (20x7? around those) room with glowing cyan floors, which was weird because the little + symbols for smooth floors were actually glowing and blurred. I looked at them with k and the game said they were "ward floor"s. Nifty.
So they kept digging down and then more of those smoothed halls from before but this time they were inhabited by these also blood red beaver-capybara-badger type of mammal things, I don't really know how to describe them. They were hostile and charged the dwarves immediately but seemed to be really bad at fighting so they missed once, causing the dwarves to counterattack with about the same level of success. Then they bolted into the darkness. I regarded them as minor annoyances and kept digging until suddenly there was a popup alert/announcement like a megabeast arriving or striking a cavern level or candy or the HFS or the great magma sea saying "An ominous presence fills the corridors!" and the unknown animals were back except this time instead of a lowercase letter they were capitals, implying they were strengthened or enlarged. This time they fared better, managing to drag a few dwarves into the dark halls, including the miners, which stopped the downward descent. This happened gradually until there was only 1 left, who was a single unarmed military dwarf. He went down the halls into the darkness, revealing it as he went, then the game changed from DF to some first person game or something that was still somehow DF? I was playing as the military dwarf and I was suddenly equipped with full armor and a fine steel sword.
So I continued exploring and killing the animals as I saw them until I entered another large chamber like the ward one. There was like this core mother beast, all tentacled and grotesque-like and attached to the hallways (which may have been living, explaining the blood red color) in the middle and the animals were dragging the dwarves (who were now dead of course) to it and feeding it. It could only take small bites from the corpses though. Guessing there was only one thing to do, I ran in and started cutting enemies up. The core was especially hard to kill, as it kept summoning or spitting out the animals which were distracting me from slashing it. After a while I managed to kill it, but its foul blood spewed everywhere, including onto the dwarf's eyes/the screen. Then there was another popup message saying "You have been corrupted." The dwarf and animal bodies from before were shifting and moving about a little, so I sunk my sword deep into them to finish them off. Then I made my way back up, but going back was slower from the "corruption". The view started tinting red and black, the character had to stop a few times to cough up blood which seemed of an unnatural color, and I thought I could see things moving in the dark ahead of me. I dragged on up until I reached the first ward chamber which was all glowy and I got a message saying "You have been cured." and then it went back to DF mode. I couldn't play the fort anymore though because the dwarves were all dead except the one I controlled, so I abandoned thinking "wow that was weird but kinda fun".
It was pretty rad.