The mistress who remarried has returned.

Su Yunxi abandoned her official post and joined the imperial family, marrying the crown prince, and her popularity soared.
Unexpectedly, the Crown Prince fell into trouble and was left to die in the Eastern Palace. Su Yunxi fell into the mire and became a rat that everyone wanted to kill.
To save the Crown Prince's life, Su Yunxi knelt at the feet of the powerful minister, begging him to help her husband escape his predicament.
The man pinched her chin, his eyes filled with amusement:
"The Crown Prince has favored my concubine for four years; now it is my turn to cherish the Crown Prince's concubine."