The butterfly demon died in that detention room.
There was only one person on duty in the office last night. He didn't know how the butterfly demon died, and he never left the company.
The man on duty said it himself.
According to the monitor video, the person on duty indeed didn't leave the office, but the video also showed that he went to the washroom and stayed there for a full 15 minutes.
"I went to answer my girlfriend's phone, just left for 15 minutes, and there was no suspicious person appear in it. When I came out, the butterfly demon was still alive," he defended himself.
"Do you need to go to the washroom to answer your girlfriend's phone?" The whole office was empty, even if he wanted to say something nasty, no one was going to check out the video the next day.
The man was a little embarrassed, "Well…"
He explained haltingly that he listened to his girlfriend's voice and did a hand job for himself…
