About two people dressed in black and wearing hoods entered an old two-story building in a slum area west of Ulin City through the back door. The inside of the building was found to be filthy and dusty upon entry.
The interior of the building is laid out like an inn, with doors spaced evenly from end to end. Strangely, it was dusty from the outside of the building to the inside, but these two people did not leave even the tiniest footprints.
The two men in black kept walking until they came to a halt in front of one of the old building's doors. One of the two people knocked on the door in a particular rhythm.
Not long after the knocking stopped, there was the sound of the door opening, but it was from behind them, not from the door they were knocking on. The door opposite the one on which they had knocked opened on its own.
