The secretary trembled nervously: "Answering Fourth Master's question, the details are still being investigated... I'll first instruct the men to collect the bodies and bury our brothers properly..."
Nangong Mo raised his voice several degrees, his eyes filled with endless gloom: "I'm asking you, who did it."
The bodyguard of the Nangong Family, exposed on the street?
Nangong Mo's anger wasn't about how many died, or who they were, but about who dared to challenge the authority of the Nangong Family and disturb things right under his nose.
Only then did the secretary nervously report: "Fourth Master, it's mainly because the perpetrator was very cunning and swift, leaving no traces, so the investigation is still ongoing..."
Basically, still investigating means they probably won't find out.