Episode 18 of Mouse begins with Daniel Lee in Ba-Reum’s apartment, asking about the past. Specifically, Ba-Reum’s desire to kill again, which was sparked to life after strangling Hyun-Chyul. The scene was also staged to spark this desire to kill again.
Lab mice indeed; Ba-Reum confronts Daniel, who admits that he knew Ba-Reum was the real predator from the very start. However, he thought Ba-Reum killed his whole family. He wasn’t aware that Soo-Ho was responsible for that. Lee also visited Yo-Han too, just to be sure.
This coincides with the moments at the fairground where we saw spatters of blood and were led to believe Daniel Lee was killed. In reality, it turns out Yo-Han was there but also a third man was too. A member of the OZ organization is who tried to kill him.
Yo-Han actually took Daniel in secretly and nursed him back to health. Just before revealing who his contact with OZ is, Hong-Ju shows up at the door. It’s just the distraction Daniel needs to slip away from the house and bundle into the back of Hong-Ju’s car.
When Ba-Reum shows up at the police station, Moo-Chi grabs him and questions the boy about the killings. Moo-Chi is enraged by what’s happened. However, he believes Detective Lee is involved and the two are conspiring together.
He also thinks Detective Lee took the missing dashcam footage and flushed it down the toilet. The scarred remnants of his tattoo is incredibly suspicious too, as if he was in a hurry to hide the OZ sigil. When the officers investigate however, the tattooist claims it spelled OJ and not OZ. However, as we soon see they could well be part of OZ as well. How deep does this organization run?
With little to incriminate both men for now (thanks to the missing dashcam footage of Ba-Reum) Ba-Reum and Detective Lee are free to go. Ba-Reum immediately heads to the evidence room and checks out the computer.
On his way out though, Moo-Chi confronts him and asks about the killings. Ba-Reum admits to killing Duk-Soo but conveniently misses out that he’s the killer for everyone else. Ba-Reum even concocts a believable story for everything else, covering his own back while acting repentant for his actions.
Moo-Chi is not sure what to believe but after hearing Ba-Reum’s statement, decides to check the validity of this. The only trouble is, Detective Lee is following him from afar.
Moo-Chi speaks to Bong-Yi and learns her story about Yo-Han being genuinely caring and helping her out on the bridge. This casts yet more seeds of doubt in his mind as he toys with the idea of someone other than Yo-Han being the killer. Moo-Chi uses his contacts to go through the evidence, back to square one again to see if he’s missed anything.
As this unfolds, we cut back and see Soo-Ho in Jae-Hoon’s house. It turns out he killed Jae-Hoon’s mother simply because she was trying to kill him.
The incident involving his Father was a complete accident, as he and Soo-Ho wrestled with a knife. On the stairs, the knife ended up wedged in Jae-Hoon’s father’s chest. As for his brother, Soo-Ho had no idea another child was in the house. He took Jae-Hoon to safety before burning the place. His sister, however, happens to be Michaela at the orphanage. Michaela is Jae-Hee.
Meanwhile, Daniel Lee goes investigating but unfortunately runs straight into OZ. At the same time, Du-Seok picks up his wife from the station but she’s holding a different child to their own. As she steps out into the road, both of them are hit by a car.
It’s a shocking moment, especially when the child’s caregiver (the one looking after the child on behalf of Hong-Ju) appears and sees this. When he realizes Eun-Chong is actually Yo-Han’s baby, Du-Seok’s complexion changes and he no longer cares about the child.
Meanwhile, Ba-Eeum realizes, through Jae-Hee’s scattered dialogue, that Yo-Han was investigating and stumbled upon details of OZ. In doing so, he realized both of them were test subjects and that Daniel Lee was telling the truth this whole time.
With Lee recovering in the basement, Yo-Han was the one working with Detective Lee and he was there that night when Bong-Yi’s grandmother showed up. Upon learning the truth, Yo-Han set out to stop Ba-Reum no matter what.
Bong-Yi too starts to doubt the Yo-Han story and heads off to find the autopsy report for his body. There, she realizes there’s no scar on his arm – and also learns Ba-Reum never reported this when Bong-Yi told him to.
While Moo-Chi pieces together the facts and starts to come to the correct conclusion, Bong-Yi heads over to Ba-Reum’s place. With the man passed out on the sofa, Bong-Yi lifts up his sleeve and sees the scar on his arm. Now she knows the truth. And Moo-Chi does too when he heads back to the prison and pieces together everything. Game on.
Mouse returns with more answers this week, explaining just what Daniel Lee’s ties are to everything that’s been going on. So it seems he wasn’t the one to die that night and infact it was actually this OZ member. But where did his body go? That’s still a mystery of course but it does explain why Lee is still alive. It turns out he’s not a hallucination after all.
Meanwhile, Bong-Yi and Moo-Chi both piece together the truth and learn that Ba-Reum is the Seven Deadly Sins killer. Quite what will happen with this remains to be seen but I’d imagine Ba-Reum will either be killed or arrested for what he’s done. There surely can’t be a happy ending for him.
Learning more about Ba-Reum/Jae-Hoon’s past and family is definitely welcome though, with the irony being the killings inside the house were technically accidental. Jae-Hee survives and she’s actually Michaela at the orphanage. On reflection, this was foreshadowed quite well but definitely caught me off-guard!
It also seems likely that both Jae-Hoon and Yo-Han were switched at birth, which backs up the whole psychopath gene situation we’ve been hearing so much about. If this is the case, could it be that the OZ organization are responsible? Could this all be part of the game?
With all that in mind, Mouse continues to weave an intricate web of plot twists and drama. While the show oftentimes ties itself in knots that are hard to undo, this one is undoubtedly a gripping and engaging watch despite its flaws.