The so-called Secret Palace was defined not only by secrecy, but also by the status of a palace. Who alone had the right to use a palace? Aside from the monarch, no one else possessed such qualification.
Therefore, to put it another way, the Secret Palace was in all likelihood the precursor to the Grand Court of Justice of later generations—a penal institution established specifically for members of the royal family and imperial relatives, operating independently of the Commandant of Justice and the Ministry of Justice.
Zhao Gao originated from the Secret Palace, meaning he was very likely a scion of the Ying clan, perhaps implicated because an elder had violated the laws of the empire and the statutes of the ancestral house.
Chapter 469