human
Subaru:  The inside should have been a cylinder, a simple extension of all the previous floors, but when Subaru entered the room, he was greeted by a strange expanse that spread out in every direction. The area should not have been noticeably larger than the previous floors, but the overwhelming whiteness made it impossible to see the walls, making it feel endless. Looking up, he couldn’t make out the ceiling, either. Looking down, there was just a single black hole where the stairs emerged from the floor below. Everything else was so white that he was almost scared to walk on it. He was hit by a disorienting feeling that the floor wasn’t there and he might just start falling into nothingness. The floor, ceiling, and walls were all the same. Subaru felt like he would end up wandering the vast emptiness if he lost track of where the stairs were. And right in front of him in that white space—directly in front of the stairs—there was a mysterious object floating in the air.
gpt
Subaru:  "A stone slab…?" That was his first impression. There wasn’t really any other way to describe it. It was a rectangular black slab made of a material that was almost slick to the touch. On closer examination, it didn’t seem to actually be stone, but he didn’t think it was metal, either, so he wasn’t sure what to call it. If I’m being dramatic, then maybe monolith would work. The silent monolith was floating mysteriously, hanging in the air a dozen inches off the ground. Based on its height and width, Subaru felt it resembled a large tatami mat floating in the air.
human
Subaru:  "So this strange thing is…what, exactly?"
gpt
Julius:  "If I was to put it into words, that is the device that sets up the puzzle for us." While Subaru was occupied by its strange brightness, Julius joined him in staring at the monolith. Thinking of the trouble this thing had already given him, Julius’s expression was severe.
human
Emilia:  As Emilia and the others entered the white space, they drew close, possibly to counteract the pervasive feeling of emptiness. "I’d rather not spend a lot of time in a place like this."
gpt
Anastasia:  "Agreed. Staying here too long is draining. And seeing a certain someone trip on the stairs while leaving is not good for my heart."
human
Anastasia:  "Come on, Julius, don’t be like that." Anastasia’s cheeks puffed up as she protested Julius’s joke. Judging by that reaction, she must have been the one who tripped earlier. But Subaru had no urge to laugh at that. The room had clearly been designed to screw with people’s senses. It was like a manifestation of its creator’s malice.
gpt
Subaru:  "So then, what do I do to get the riddle?"
human
Julius:  "Touch that slab and the examination will begin, I suppose."
gpt
Subaru:  "I just have to touch the monolith?"
human
Julius:  "—Monolith? An oddly fitting term. That’s a good word for it." Ignoring how Julius was impressed by the strangest things, Subaru stood in front of the monolith.