So who do you think the bad guy is? 

Call me weird but from seeing his wrists they seem smooth and quite thin. I think the killer might be apart of the younger characters, just my thought.

I think it may be Kang Hyun Jo because he has Juj or Jo Dae Jin.

I think its Kim Sol

The historian told them the significance of the two sticks in the ground. I bet he overheard them talking about it.

 Ivana Huang:

I feel like the policeman is not that innocent? 

why, me too! i'm suspecting the police officer hahahaha. remember his reaction when yi-gang asked him regarding the yellow ribbon in the earlier episode? he then asked yi-gang about the relevance of the said ribbon in the case of the dead illegal hiker. there's something fishy on the way he reacted. wdyt?

I'm highly suspicious of Lee Ga Sub's character (Kim Sol). He is so far the most suspicious character on the show.