A lot of things happen in this episode.
Zheyan and Fengjiu’s father rush over to stop the fight between her and Lord Cangyi. And NOW Cangyi says that he would like to respect her decision to call off the engagement. Her father agrees to it but wants to whip Fengjiu for humiliating him. Wouldn’t hitting her in public make the whole thing even more humiliating though?
But Lord Cangyi steps in and says that he’d take the beating for Fengjiu with real concern on his face. So there’s probably no politics behind him wanting to marry her.
Now, comes the day Bai Qian has to be picked up from Qingqiu for her wedding ceremony with Yehua. According to their rules, Yehua can’t go to escort her up himself, and Moyuan is still healing and unable to do it – which is their way of saying they couldn’t afford Mark Chao. So, the palace decides that Donghua is the man for the job.
And you just know that Donghua doesn’t take this job seriously when he doesn’t even dress differently for the trip. 
He and Fengjiu meet there, share a quick glance full of questions and each carries on with their duties.
In the cave, Bai Qian bids her parents farewell, saying that she won’t be able to take care of them anymore. I mean… When does she ever take care of anyone except Moyuan (after he was literally dead)?
A bit later, Fengjiu tries to sneak into the banquet in the Heaven court. It is unclear whether Donghua knows she’s the woman in his mortal trial, but he notices her here and knocks her off balance while she is settling down, drawing everyone’s attention to her. The man just can’t go through a day without playing pranks on someone.
I died at their way of saying they couldn’t afford Mark Chao 🤣🤣
I’m sure they tried🤣
And here is where the book actually starts… In the book is clear he does not know who FengJui is, but he notice her right away, and makes him “curious” to know why she is still using the mourning clothes. The fox part and the mortal part are mention as a rememberance of the past when Feng is trying to move on of Donghua’s Love… so when I saw the drama I just asume he did not know, but now that I read this, you’re right, it’s not clear. At this point I really hoped Quinti will appear later because I wanted him to be the 2nd lead really bad
Sometimes I thing he cultivates himself by making pranks on people XD