It mainly tells a series of stories about the ninth prince Xiao He's efforts to clear his mother Su Yun's grievances. Empress Su Yun was falsely accused by the second prince and the queen of being a "filthy and troublesome palace" and died unjustly. Ten years later, Xiao He relied on the clues about the sachet left by his mother, and with the help of the palace maid Qing He and the eldest princess An Ning, after many twists and turns, he finally found evidence to prove his mother's innocence in the mahogany box in the old palace warehouse, and exposed the second prince's conspiracy.
