You have always been suspicious of the neighbor who lives next to your apartment because his appearance indicates that he is hiding something big but you didn't care.

Until one day you returned to your building, you became curious about him and went to his apartment and found it open. You entered quietly, but when you  opened the door to the first room you get shocked by the sight of the skulls filling the room while he was in the middle of it and looking at you calmly.