Yang Xiao held his breath, focusing intently as he listened to the sounds within the room.
With his acute hearing, he could completely make out the noise from inside the room through the door.
If someone were to open the door, that would be best, but if not, he would have to think a bit more.
The Lone Wolf either had heard some rumors and fled from this place, or after hearing the knocking, he was unwilling to open the door, or perhaps he was in such a deep sleep that he didn't hear the noise.
Under normal circumstances, the last assumption simply wouldn't hold true. Let's not forget that the Lone Wolf's profession was an assassin, and with an assassin's alertness, it's not just knocking— even footsteps would easily awaken him.
Which means, if the Lone Wolf didn't open the door, there were only two possibilities.
The first possibility was that the Lone Wolf wasn't in the room.