The Loss She Suffered!

The Emperor asked Huang Feiye to speak. Huang Feiye who was still in his armour, half knelt in front of the Emperor. He explained how while all the previous Emperors had a single group of secret guards, the immediate predecessor of the current Emperor had two sets of secret guards as he didn't trust them either.

The basic principle of the secret guards is that the Emperor only knows the leader and only the leader knows all his members and the members didn't know who other members were but only the leader. The strength of the secret guards is that they hid in plain sight and they just followed the orders of their leader obediently.