The two remained in a standoff for a while, then Xu Shuo moved his mouth.
He didn't make a sound, but Manager Zhang's pupils suddenly contracted. This uncontrolled reaction let Xu Shuo know he had found the right person.
This also went back to the twelve individuals the male waiter had mentioned earlier – Manager Zhang was one of them, and the only one who had taken action after the power outage.
As for why the person looking for a trade produced a knife wound, Xu Shuo really wasn't very clear about that.
At the time of the chaos on the second floor, Xu Shuo's attention was mostly on being wary of the Capital Commandant. He didn't pay much attention to other places affected by the spread of the sonic wave. Only Room 304 continued fighting after the battle on the second floor ended.
Manager Zhang hid in Room 303 even earlier than the male waiter, which meant he must have been the first to get to the third floor after the power outage.