Episode Summary
Wu Zhen confronts the Wordless Book about its lies and learns she must stay in the Demon Market to suppress the Yuan Dan. After a sad farewell to Shuang Jiang, Mei Si accidentally swaps souls with Liu Taizhen using a pair of cursed puppets. The episode ends with Wu Zhen coldly telling Mei Zhuyu their paths have diverged and asking for a divorce, leaving him shattered.

Spoiler Alert
Moonlit Reunion: Episode 30
This episode was a whole mess of feelings, and not all of them were good. We got lies, goodbyes, and a body-swap plot twist I did not see coming.
Waking Up to Lies
Wu Zhen vs. The Wordless Book
Wu Zhen wakes up in a healing pool. The first thing she sees is the Wordless Book just standing there. She looks at it for a long time. Then she finally asks the question that's been eating at her. Did the Book know about Mei Zhuyu and Changxi Palace all along?
The Book doesn't say anything. That's a "yes" if I've ever seen one. It tries to justify the lie. It reminds Wu Zhen that she always wanted to experience everything, good or bad. The Book admits it didn't expect things to get this bad. It also didn't know the Yuan Dan was inside her. For the first time, Wu Zhen looks at her oldest companion and feels like she's looking at a stranger. It's like she never really knew the Book at all.
The Morning After
Mei Zhuyu's Lonely Return
Back at the house, Mei Si is a wreck. He's been up all night worrying. Xuanhui finally comes back with news from the Demon Market. There was a huge incident. The Cat Duke and Snake Duke were both hurt, but their injuries aren't serious. Mei Si is then hit with the big shocker. Mei Zhuyu was the cause of all the trouble. He's stunned into silence.
Wen Hua and Ming Zhuang are sitting at a table full of untouched food. They know Mei Zhuyu and Wu Zhen never came home. Just then, Mei Zhuyu walks in alone. He looks completely defeated. Everyone expects Wu Zhen to be right behind him, but it's Mei Si who bursts in instead. He's furious at Mei Zhuyu for keeping secrets. But his anger quickly turns into begging. He wants Mei Zhuyu to get him into the Demon Market so he can see Liu Taizhen.
Meanwhile, Liu Taizhen is personally treating Wu Zhen's injuries. Wu Zhen finally understands the heavy duty of the Cat Duke. She has to use her own body to contain the Yuan Dan forever. The Wordless Book waits outside all night. Liu Taizhen eventually comes out and tells it that Wu Zhen has to stay in the Demon Market to recover.
A Bittersweet Farewell
The next day, Mei Zhuyu gets a message from a paper crane. His senior brothers are leaving Chang'an to go back to Changxi Palace. He rushes to see them off. He tries to give the Changxi Jian to his second brother, Xiao Mu. Xiao Mu refuses to take it. He says their master gave it to Mei Zhuyu for a reason. He also says the duty of a Heavenly Master isn't about a weapon. He tells Mei Zhuyu to keep the mace and protect justice, because there are still demons hiding in Chang'an.
Mei Zhuyu takes the mace back. He feels someone watching him and turns, but no one is there. It was Wu Zhen.
Shuang Jiang is on the road back with his brothers. He finds Hu Zhu waiting for him. Wu Zhen sent her to say goodbye for her. Hu Zhu passes on a message. As long as the Yuan Dan is inside her, Wu Zhen swears she won't let evil run loose in the world again. Before leaving, Shuang Jiang gives Hu Zhu the flatbread he was carrying. They look at each other for a moment and then part ways for good. Hu Zhu watches him disappear, letting their past fade away.
A Seriously Freaky Friday
Mei Si's Big Mistake
Mei Si will not give up. He pesters Mei Zhuyu all day, trying to get into the Demon Market to find Liu Taizhen. Mei Zhuyu is firm. There's nothing he can do. So Mei Si sits in front of him, complaining loudly. He starts fiddling with a pair of old wooden puppets sent over by the Duke of Yu.
Suddenly, he feels dizzy. You can probably guess where this is going.
The Soul Swap
He has swapped souls with Liu Taizhen. Now, Liu Taizhen is trapped in Mei Si's body. Mei Si's soul is in Liu Taizhen's body.
Inside the Demon Market, Mei Si realizes he's a woman and starts wailing. Wu Zhen shuts him up and demands to know what happened. She immediately suspects the wooden puppets are the cause. Mei Si doesn't have time to explain everything. He grabs Wu Zhen and drags her out of the Demon Market. He's desperate to find his body and switch back.
The Final Conversation
A Marriage Ends
Mei Zhuyu is waiting in the courtyard. He has snacks and wine all set out on the stone table. He knew Wu Zhen would come. He knew she would be in her demon form. He also knew she had something to say. He apologizes before she can even speak.
But Wu Zhen is cold. She tells him she understood his choice the second he opened that barrier. They can't erase their past. They can't ignore that they've tried to kill each other. The fighting is over, but they walk two different paths. One is an immortal, the other a demon.
Mei Zhuyu tries to explain. Wu Zhen doesn't want to hear it. She says their fate together has run its course. Then she asks for a divorce.
In a last-ditch effort, he kisses her. She just pushes him away. She turns and walks out, disappearing into the night. Mei Zhuyu is left alone in the courtyard with the untouched food and wine.