Even Zhang Qing did not know too many of the details, because the Internal Guard Bureau only emerged after His Majesty ascended the throne, moving from the shadows into the open. During that time, no one knew of its existence.
When His Majesty's so-called uncle attempted rebellion, it was the Internal Guard Bureau that detected it first, covertly making preparations to defend, thus preventing a major disaster.
As time passed and the court situation gradually stabilized, with His Majesty firmly in power, the role of the Internal Guard Bureau began to diminish, once again shifting from the limelight back into the shadows and gradually disappearing from the court's view. Cao De also adapted to the situation by stepping down, showing up only occasionally and no longer meddling with affairs.