Stratum 1: The Visitors

One night, two men meet in an abandoned building, and share their memories about early lives in their hometowns. They leave this building and continue to roam in the night, then they find themselves return back to the abandoned building: it looks more unfamiliar now, then it collapse down, then it's gone. They leave this place and pass by more ruins and finally reach to the edge of the city and arrive at a hill which is constructed by piled-up construction waste. On the top of the hill, they see the railway that leads to their hometown.