Maomao meets with Fengming and details her deductions. The “deep clean” of Ah-Duo’s pavilion was only an excuse. The reality is, Ah-Duo is leaving the Rear Palace, because after she gave birth to her son, she was no longer able to bear children afterwards. When Fengming says it’s none of Maomao’s business, Maomao says it is, because her father was the attending doctor.
As for Ah-Duo’s son, Fengming fed him honey, not knowing that it could be fatal to infants. Fengming only learned that she caused the death of Ah-Duo’s only child when Ah-Duo befriended Lishu, who herself nearly died as an infant after eating honey. Not wanting Ah-Duo to put two and two together, Fengming saw to it Lishu was kept away from her lady’s pavilion, only for her to return when the new Emperor came into power.
Maomao deduced that to protect Ah-Duo, who could not bear children, Fengming poisoned Lishu’s soup. Once Maomao delcares this and Fengming does not dispute it, there isn’t really much else to say. But then Fengming breaks down, demonstrating to Maomao that she kept Ah-Duo closer to her heart than Maomao could ever imagine keeping anyone. She knows Fengming is doomed, but still wants to do all she can, so she merges her two motives into one: protecting her lady, Ah-Duo.
Maomao doesn’t end up telling Jinshi anything; Fengming turns herself in, and Maomao simply tells him her motive was to protect Ah-Duo’s status as a concubine of the Rear Palace. The thing is, the decision for Ah-Duo to depart as concubine was made by the emperor long before Fengming’s actions came to light.
Maomao, ever the poison junkie, tastes the nectar of an azalea, and Jinshi follows her lead, until she tells him it’s (non-lethal) poison. Fengming is then executed, and one night when Maomao can’t sleep she climbs the wall to view the stars, and is soon joined by Ah-Duo, who offers to share her booze.
Ah-Duo confides in Maomao that after her son “left her”, she returned to being the emperor’s friend, not his concubine. She actually never quite felt right in the position of concubine, and was eager to pass it on to someone more suitable, only to cling to it for years. Before parting with Maomao, Ah-Duo pours out some of her booze into the moat where the servant took her life, noting just as Maomao did that it must have been cold and painful.
Later, when Maomao climbs down the wall, she is startled by Jinshi and falls, but he catches her. Rather than let her go at once, he embraces her tightly, claiming it’s too cold. Maomao notices he’s drunk and he reports that “someone” (Ah-Duo) drank him under the table and ran off. When he starts to weep, Maomao lets him continue to hug her.
The next morning, Ah-Duo departs the Rear Palace in a ceremony full of pomp. She hands the crown of the Pure Concubine to Jinshi, and Maomao realizes there’s a very good reason the two resemble one another so closely: there’s a good chance Jinshi is her son. Maomao thinks to when Ah-Duo said her son “left” her, rather than saying he died, and considers whether her infant child and the Empress Dowager’s were swapped.
That would mean that it was the Dowager’s child that Fengming accidentally poisoned with honey, while Jinshi grew up to become the chief administrator of the Inner Palace (whether he’s actually even a eunuch remains to be seen). When Lishu chases after Ah-Duo and bids her farewell, Maomao observes that Ah-Duo looks every bit the caring, loving mother.