Loving this drama and all the mysteries that's presented. I wanted to start a discussion to talk about theories to try solve those mysteries ourselves.  The big questions I think the gang are trying to solve are:

1. What happened to JingYu's dad? 

We know that he survived the fall and became the witch doctor, also that he's currently dead as we saw in the previews. But did he commit suicide, or was murdered? He clearly went through a lot of trouble to leave the clues for someone to find him. Also we know that the head eunuch tried to kill him 10 years ago.  

2. What is Duke Chang Planning? Clearly he thinks he's the rightful emperor and want to take the throne. But how did he get back into court without others recognizing him? Who actually knows what who he is?  

3. Are JingYu and JingLi actually brothers? 

4. Who is creating all the fake money? 

From what I'm able to gather so far it seems like there's 2 major "bad guy" camp. The head eunuch and duke of Chang. Does anyone know what exactly the head eunuch is trying to do? Clearly he doesn't want people to know what happened during the war that "killed" JingYu's dad, but what's his motivation for doing what he is doing? How does the current emperor play into all this?