After Master Jiang Tai left, Yang Ning didn't leave the study room and accompanied Zheng Liang while he was deeply lost in thought.
It was a serious matter. The Empress of the Empire has been involved in a possible attempt to murder His Majesty which could bring the whole Empire into turmoil.
Not only that, Master Jiang had previously revealed that His Majesty's condition is similar to the state of Zheng Liang's mother before she passed away from sickness.
She was also showing the symptoms of being poisoned and was bedridden for quite some time but there was no sign of a poisonous element in her blood. Because of this, she couldn't receive the proper treatment and antidote in time and passed away leaving her young child behind.
If these two cases are related then there is a high possibility that Yang Lingxin who was just a concubine at that time was also involved in the murder of Zheng Liang's mother and the First Empress Consort of His Majesty.