Mysterious Place

This is a weird place There is an overlap in time here A more strict level There is only one door leading to the exit get lost in it Or... Escape Gong Su and her brother strayed into a bizarre city. While wandering around, Gong Su walked down a staircase After walking down the first floor, the stairs mysteriously disappeared, and the stairwell also disappeared. What's even weirder is here Gong Su met another self one future self