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It was as if he were playing an adventure game; he could review maps that were already illuminated from a fresh perspective but had no way to go to those places that had been dark from the beginning to end.
Without time to think further, he quickly followed the others into the stairwell.
After entering the stairwell, he didn't rush downwards but looked up first.
The entire stairwell seemed to embody the Fibonacci sequence; when looking up, it was impossible to pinpoint his location—just a spiral extending endlessly into a pitch-black vortex above.
He then looked down and saw the same Fibonacci pattern, another pitch-black vortex.
Had it not been for his subconscious belief that the ground beneath his feet was "down" and above his head was "up," he would have been unable to distinguish between the concept of up and down.
He looked again at the location of the stairwell, only to find that the door had disappeared into thin air.