C245 Unreasonable play

This was a hotel, even if there really was someone coming, it shouldn't be too excessive, right? Maybe it's a hotel attendant?

After some thought, she turned to the door and asked, "Who is it?"

"Dong, dong, dong."

There were several more knocks on the door, but she did not get an answer. Who was the one that had nothing better to do but to keep quiet? The more she thought about it