The first kind, the two of them formed an alliance for reasons unknown, with Xia Qing working for the Fourth Prince.
The Fourth Prince, however, hides behind the scenes, giving the impression that he has not recovered from his illness, deceiving the world. In reality, he is hiding in the background, manipulating the court through Xia Qing.
The other kind is a cooperative relationship, but not an alliance. This sounds contradictory, but it's not. Xia Qing and the Fourth Prince can cooperate on certain matters, but each has their own agenda and they are calculating against each other.
Gu Chengyu leans more towards the latter; after all, Xia Qing wouldn't willingly submit to the Fourth Prince.
As for the mysterious person, Gu Chengyu had already guessed. There were only a few people in total, and Xia Qing came to his mind first.
Guo Moruo watched Gu Chengyu silently, seemingly contemplating something. Then he folded the letter and returned it to her.
