Spoilers aplenty.

Let me begin with my ultimate theory on this show, which I haven’t yet given up on, despite much evidence to the contrary. It is this: Lee Seung Gi’s character, Jung Ba Reum is the serial killer the detectives are hunting for. He’s either the real son of Han Seo Joon, the Headhunter, or the other baby who’s mom also participated in Dr. Daniel Lee’s research on the psychopath gene. His real self is the psychopath serial killer.

In episode 9 we are given more insight into what happened to Ba Reum. By a series of quite interesting incidents, the Headhunter serial killer, also brilliant neurosurgeon, was called in to perform brain surgery on Ba Reum to save his life. As his brain was handy, Yo Han’s brain was used. Since Yo Han was in theory the killer Detective Go and everyone was hunting for–the one who began as a child with a serious beef with God, Ba Reum now has the mind of a serial killer and doctor. He’s brilliant and makes a great detective. He’s also now plagued with thoughts of killing people and is starting to act on it.

Here’s where my theory comes in: I think that Yo Han is another misdirect by the writers. I think he’s actually innocent, and may not even be the Headhunter’s son, but another boy who was simply a genius. Do I have evidence for this? He told his mom, “Your son is a killer,” not “I am a killer.” PD Choi had a love life and a baby with him and states they are the same. How exactly they are the same, I don’t know. The important thing is she really doesn’t believe he’s a psychopathic killer, not deep down in her heart. The three biggest reasons I have for thinking that Ba Reum, not Yo Han, is actually our killer is that 1, Ba Reum’s personality didn’t seem quite genuine at the beginning of the series–a somewhat dumb, simple guy with a heart of gold, and out of sync with the gritty world around him. Could he be putting on a show, much like his magic show he performs at the prison? 2, and this is a long shot, but significant: In the scene where Yo Han attacks Ba Reum, we get a glimpse of Ba Reum’s face just before they fight. The expression is not the Ba Reum we know, but an intelligent man, eager for the fight, a horrible killer who, I think, Yo Han has actually been trying to find and to stop. Like Detective Go, Yo Han surely thought such a man should die and probably that beating his head in with a hammer was even too good for him. This relates to 3: for some reason, Yo Han had a collage of pictures of Ba Reum in the secret room in his basement. Inexplicably, Ba Reum knows about this room and sees the collage–that, I don’t think has ever been explained yet–and also seems to know exactly why Yo Han has such a collection. Yo Han has perhaps been hunting him, the genius hunting the psycho.

So Ba Reum thinks he now has a serial killer’s brain in his head, but really he was the serial killer and now he has a partly good and intelligent brain taking over his body, fighting against his desire to kill, kill, kill. The wanting to kill simply comes out because it’s the larger part of his brain, for now, and something that Ba Reum originally hid from everyone, except his victims. Ok, probably it’s not how the story’s going to end up, but I like the theory, and I’m sticking to it for now because it’s more intriguing to me than the more simple good guy being taken over by serial killer brain.

To the episodes:

We are now getting a lot of backstory and ends starting to tie up in a very confusing web. Episode 9 basically confirms that the lifetime imprisoned Headhunter did indeed do brain surgery on him and used Yo Han’s brain. In addition, with Ba Reum’s genius he’s able to figure out that the Headhunter wasn’t just killing people, but was doing experiments on them. Basically, humans are rats to this awful neurosurgeon who thinks he’s God.

In addition, we find out more about the Headhunter’s past, and insight into both his creepiness and his genius. Turns out Dr. Daniel Lee is very smart, too, and helped him solve a difficult medical case. Daniel was a janitor at the hospital at the time and admires the neurosurgeon. The two become friends and the Headhunter give Daniel the idea to search out not a good gene, but a bad gene, a psychopath gene, and use that to rid the world of bad people. Later, the Headhunter regrets setting him on such a course–he really didn’t think he’d succeed at it. The Headhunter also blames Detective Go, the child, for ruining his experiments, as it was child Go who helped the police catch him.

Episode 9 deals largely with the knot killer, who everyone thought was a police detective who also has a very suspicious lawyer son. This knot killer may or may not be the same person as the one with the beef with God and who sets up his victims to be giving the finger to the cross. It’s confusing to me, and sometimes it seems it’s meant to be the same person, and other times not. In any case, Detective Go takes the fall for the murder of the officer everyone thought was the knot killer. He’s happy to go in, so that Detective Park Du Seok’s wife doesn’t have to go to prison. Detective Park is the one who was trying to catch the Headhunter 25 years ago. The Headhunter took his kids as consequence and killed them. However, this is also mixed up with the knot killer who supposedly was the one who really killed his daughter (the son was killed by the Headhunter). Whew! Confused yet?

But the officer is not the knot killer, it is actually his son, which, if you’re paying attention, doesn’t come as a great surprise. Ba Reum with his genius figures this out and in addition figures out that Detective Park’s wife did not kill the officer in the hospital, and neither did Detective Go. Turns out the officer buried a different little girl that his son, the lawyer, and the real knot killer actually killed, and he pretended she was Detective Park’s daughter. So where’s Detective Park’s daughter buried? We don’t know. Is she still alive? We don’t know. So, Detective Go gets released from jail, foiling the plans he had to murder the Headhunter in prison. Ah, well.

The lawyer, Woo Byung Chul, son of the police officer and, drumroll, a woman who participated in Dr. Daniel Lee’s study into the psycho path gene, is the knot killer. It’s implied he’s also the cross killer and that Yo Han is innocent. I think they are mixing up cases or something, but I do agree that Yo Han may be innocent. If so, how does that explain what’s happening in Ba Reum’s head? See my theory above.

We also get some interesting stuff with PD Choi and the Headhunter. She went to interview him in prison at one point and also planned to kill him there, but chickened out. Is she a former victim of his? At one point, in talking with Detective Go about the Headhunter’s son, Yo Han, and their relationship, she says, “he’s like me.” Interesting.

Ba Reum is seriously struggling not to kill animals and people. His cat’s afraid of him and he even tries to strangle Detective Go, who comes to his house drunk. He also understands that the memories he has of the yellow-jacketed kid, the one in the beginning who brings the mouse to the snake’s cage is not him. He bases this assumption on a picture his aunt gives him. It’s of him as a little boy in Kindergartener and the boy is the not the same one he remembers. Not sure about that one, as a first person memory, you wouldn’t really even see your own face, so if he’s seeing it as a third person memory, the little boy wouldn’t be him anyway, but, meh, details. There’s no reason to think that little kid is a psycho, just that he somehow had the mouse that the Headhunter did brain surgery on to make it more aggressive. Who the older girl is that stomped on the mouse, saying it needed to die, we still don’t know.

Episode 10 is much backstory, too, dealing a lot with how parents handle their psychotic kids. The mother of the lawyer knot killer didn’t end up very well, she ends up dead at the hands of her own son, who grew up to have his dad, the officer, cover for him so he could kill a lot of women. It’s disturbing stuff, basically because the mom does try to kill both her and her son to preserve other lives, and also because she has a graphic connection with the Headhunter’s pregnant wife at the end. They definitely are not short on the horror in this show.

We are happy to find that Detective Go is still alive and that his friend didn’t strangle him to death or pummel him with a rock. No, Ba Reum pummeled his own hand to get himself to stop choking the detective. Go really has no clue something strange is going on with Ba Reum, and it may take a lot to convince him that Ba Reum is or is now a killer that must be stopped by him.

Interestingly, Ba Reum goes to church to ask God to stop him killing, much like our psycho boy from long ago, the presumed cross killer. The cross killer is back, but it could be a copycat or accomplice, and in the end it’s a bit muddled with the knot killer. Go and Ba Reum definitely now have evidence against the lawyer, who is now apparently guilty of both the knot and the cross murders and someday I’ll watch it all again to figure out the connection, but while Go is actually fine that Yo Han wasn’t a killer, Ba Reum is not. Of course, this is because if Yo Han is not a killer, what then is going on in Ba Reum’s head? Aha. See my idea above.

The end has a great villain scene where Ba Reum confronts the lawyer in a warehouse and gets him to reveal his true self. Song Jae Hee does a great job in this scene, using all the creepiness he can. With his good side angered, Ba Reum’s bad side takes over and he actually kills Jae Hee. In episode 11, Ba Reum tries to turn himself in, but it doesn’t work out the way he wants–Detective Go and forensics go to investigate the warehouse, but there’s no evidence of a murder there! Still, Ba Reum is certain he did it. He wasn’t hallucinating. But, with video footage of the lawyer escaping the country surfacing, there’s nothing Ba Reum can do. Everyone just thinks he’s having complications from his brain surgery. Well, he is, just not in the way they think.

Ba Reum is now assigned officially to the Evidence room team along with Detectives Go and Park. It’s a recipe for something, but I’m not sure what.

In a twist, we find out why there was no evidence against Ba Reum: Dr. Daniel Lee is somehow still alive and has been keeping tabs on him! When Ba Reum asks him, didn’t Yo Han kill him, Dr. Lee brushes the question aside as irrelevant to the moment. So! Considering my theory above, let me add to that: What if Yo Han was working with Dr. Lee to track serial killers–because he’s a genius, not a psycho–and what if they were both tracking Ba Reum back in the day? Just, ideas. At any rate, Dr. Lee gives Ba Reum an opportunity to become Dexter: to be a serial killer that hunts and kills other serial killers. Use his instinct to kill for a sort of good. Ba Reum tells him he’s crazy, but the rest of the episode he’s clearly in a losing battle against the evil side of his brain.

Not only is Ba Reum clearly harming his cat and not remembering it, he now does remember killing his bird in the cage while recovering in the hospital and is horrified. His aunt has a son, his cousin, that he doesn’t remember, but bonds with instantly and stupidly takes the kid from his babysitter to come over to his house, hang out, and see the cat. Never do such a thing without getting parent approval, never, never! Of course the awful happens, Ba Reum snaps into his psycho mode and it appears he will kill the boy.

We also get to spend some time with Bong Yi, who wants to deal with her rapist herself. She doesn’t want Detective Go or Ba Reum’s help, and she’s determined to make that man avoid her. But the tables are turned at the end when she realizes the predator is a pedophile–she’s too old for him know and he’s hunting a young girl in her neighborhood. Bong Yi valiantly steps into action to save the girl’s life and she puts up quite a fight. The ending scene is her fading into darkness, asking the man standing over her to help the child. The man is Ba Reum and it appears he may have taken Dr. Lee’s advice to heart and is planning to focus his killing instinct on the monsters who harm other people.

Whew! There’s so, so much to this show, it’s hard to keep up. The beginning of episode 11 also has a great scene between our cross killer as a boy and another boy who is good who he admires and wants to be like. Are these two our genius and our psycho? It appears so. I’m curious to see if this psycho boy is actually the cross killer or if he only could have been and ended up choosing a different path. Maybe that’s to come. We’ll see. There’s also another detective acting very suspiciously who is possible another serial killer or maybe just a minion of the Headhunter. We’ll see. Can’t wait to watch episode 12 tonight. I’m sure it will bring all my theories to ruin. Oh well, that’s what great stories do. The acting is all spot on, and the directing good too, only one almost doesn’t notice it trying to keep up with the web of a plot.