Many things start to make sense but still more to come
In this episode there are many things that become clear about Ba Reum past. Moo Chi is getting closer to undercover Ba Reum involvement in the crimes. Even Bong Yi start doubting about Yo Han being the serial killer. It seems that all characters are getting a ride on a rollercoaster to a big ends. If it doesn't disappoint in the last 3 episodes, this episode could be the definite one that would make you wanting to re-watch the whole drama again from the beginning once it ends. Very well executed episode that unravel many mysteries and at the same time, it presents you with new questions to be answered.
Changing actors when there are only 4 episodes left is just wrong
I knew before this happened that it will be a bad decision. Bae Sung Woo replacement because a scandal of his offence of driving drunk is from my view too exaggerated. But I can understand that for Korean this dangerous behaviour is a bad example and I could accept their reasons to fire Bae Sung Woo and don't letting him to continue in the drama. However, the solution they found for not having this actor anymore in the drama was the worst. Replacing the character with a different actor and pretend nothing happened does not do the trick with the audience. Jung Woo Sung did a good imitation of Park Sam Soo character, but as a viewer, I can't forget is not him and this switch it just make you realise that is a fictional drama and doesn't let you to immerse in the story. Screenwriters could have come up with a better plan of taking Sam Soo character out of the drama and perhaps introducing a new character with a different personality, so there is not need of imitating other actor performance.