Lord Xu entered Old General Liu's mansion and took Old General Liu away so easily because Old General Liu himself was waiting for someone to come for him.
Since the men Old General Liu had dispatched did not return, he knew something had gone wrong, and he grew restless.
Once those men failed their mission and were captured, it would spell catastrophe for the Liu family.
The men sent out were all soldiers he had brought back from Jiangnan; they were his personal guard. Moreover, they were his secretly trained private army.
Old General Liu knew disaster was imminent, so he arranged for his sons and grandsons in the mansion to escape overnight, taking the female family members with them.
They fled to Jiangnan, where his eldest son was stationed at the border; that was also their territory.
As long as they reach our territory, what can Xiao Yunjing do to us?
So, when Lord Xu arrived at Old General Liu's mansion, only Old General Liu himself remained.
