The Second Prince's questioning had made the Captain of the Imperial City Imperial Guards feel awkward as he did not know how to provide an appropriate answer.
Strictly speaking, the Imperial City Imperial Guards answered solely to the Emperor and could only be redeployed under the command of His Majesty. The act of redeploying the army by anyone else would be in violation of the law.
Yet, the black-clad imperial bodyguard was an important figure who served the Crown Prince. So, they followed his order and surrounded the restaurant in desperation of wanting to please and flatter the Crown Prince. They had never expected to run into and get busted by the Second Prince.
The Captain of the Imperial Guards understood very well that the Crown Prince and the Second Prince were rivals, competing over the throne. For such competition, only until the very end could one tell who the winner would be.