From discovering who was behind several suspicious deaths to finding out what happened to his son Do-yoon (Jung Si-on), Se-won has had a lot to contend with over the course of the six-episode series.
Based on the webtoon of the same name by Hongjacga, Dr. Brain has some unexpected twists and wild moments that were certain to keep viewers on their toes, as explained to Newsweek by the director and some of the cast.
Here, Newsweek breaks down the most surprising moments from the K-Drama.
Warning: This article contains mild spoilers for Dr. Brain
1. Se-won syncs his brain with a dead cat
Probably one of the most surprising things about the show is that Se-won doesn’t just brain-sync with recently deceased humans, he can do the same with animals.
In one episode Se-won syncs his brain with his cat, who died after being hit by a car, in order to see if the feline had witnessed anything untoward in relation to the suspicious death of his wife Jae-yi’s lover Lim Jun-ki (Kim Joo-hun).
Through this experiment Se-won is able to see the cat’s memories, but that’s not all as he also learns its abilities—like being able to see at night and climb trees with ease— which he uses to find Jun-ki’s missing daughter Hee-jin (Han Cho-yi).
Director Kim Jee-woon spoke with Newsweek about the plot, and said that while Se-won’s brain sync with the cat was a storyline from the original webtoon he was keen to make it his own.
“I tried to tackle that part a little bit longer and add more details and scenes to how the main character tries to uncover the mystery using those abilities,” Kim said.
“So it’s not necessarily a superhero kind of vibe. But when we formed the structure of the storyline in the beginning we thought it would be interesting if not just the memories but the habits of that person, and the physical traits could actually be transferred together with that to the protagonist.
“We thought at that point, it will be more interesting to go beyond just humans and kind of synchronise with animals so that he could have a physical ability that is superior to a typical human being.
“And that’s why we decided to go with animalistic traits, and I tried to direct it in a way that he would use those traits to help him solve the case.”
Lead actor Lee also told Newsweek he found the unexpected twist “really fun” because it gave him the change to think about “how I [was] going to portray a cat man.”
2. Kang-mu is a ghost
Another unexpected moment is when Private Investigator Kang-mu (Park Hee-soon) learns he isn’t actually alive, and is just a memory of himself projected by Se-won.
The character met with Se-won multiple times throughout the show and helps him out with his investigations, before eventually acting as his conscience.
Park reflected on this revelation with Newsweek, admitting he found it “tricky” to portray Kang-mu without giving the twist away to viewers.
He said: “For Kang-mu, he exists in the imagination of Se-won, but at the same time he has ego so he can speak and think for himself.
“So, I think that kind of borderline was very tricky to define initially, and we tried to really think about the role of Kang-mu throughout the series with the director.”
Park went on: “That scene where Kang-mu realises that he is [a ghost] that I think was one of the most important and challenging things for me. And there were some simple trial and errors that we went through [because] we actually [filmed] that scene only four [or] three times.”
3. Lieutenant Choi believes Se-won’s brain-sync theory despite him being a suspect for murder
During the course of the season Se-won becomes a murder suspect, namely because of the suspicious manner in which his wife came to be in a coma and her lover was killed.
Despite his strange behavior, Lieutenant Choi (Seo Ji-hye) starts to believe Se-won’s claims that brain-syncing allows him to see the memories of the dead, and that he can find Jun-ki’s daughter Hee-jin.
As an officer of the law one would think she’d prioritize logic rather than allow Se-won to go so far as to help their investigation.
Seo told Newsweek that Lieutenant Choi’s reasoning behind this is because she was at her wit’s end with the investigation, so she had “no choice” but to believe him.
“We first start off with a murder case that I have to solve which turns into kidnapping case, and so I think at this point she’s feeling a little frustrated about how she’s not really getting anywhere,” Seo said. “And the other important part is that there cannot be any more victims, and so I think, at the end of the day, she can’t believe it but she’s forced to.
“And she takes a leap of faith [because] she has no choice but to rely on this information… even with logic [thrown] out the window.”
4. Dr. Hong’s dark past
Another big twist is that Dr. Hong Nam-il (Lee Jae-won) was in fact linked to the villain Dr. Myung (Moon Sung-Geun) as he worked with him on his brain-sync technology.
They did this by experimenting on homeless people in America, people they believed would not be missed if they died from the brain-syncs.
While Dr. Hong is Se-won’s friend he is partially responsible for his son’s disappearance, but actor Lee believes he’s “a good guy” who was important in helping solve the mystery.
Of portraying the character, Lee told Newsweek: “It was very apparent that he held the key to the secret of the mystery that we’re trying to solve through this storyline.
“I [had] a lot of hopes and expectations for this character because he looks like a good guy, but he has a lot of dark secrets.
“I didn’t really want to express explicitly everything and unravel these dark secrets [too early] because firstly it could actually confuse the audience and secondly, I didn’t want to give out more information than I needed to.”
5. The hidden world inside the brain
The Dr. Brain finale featured quite an intense turn of events which saw Se-won enter his son Do-yoon’s brain so that he could save him from being all but killed by Dr. Myung, who planned to drive the boy’s psyche out of his own body.
This culminates in the three character’s being thrust into a hidden world inside Do-yoon’s subconscious that can be manipulated at will, whether that be done by Se-won, his son, or Dr. Myung.
While this new world is only featured for a short amount of time in the Apple TV+ show, it allows the characters to subvert realism and also made viewers question what is humanly possible.
The scenes inside the brain also make for a thrilling climax to an action-packed K-Drama.
Dr Brain is available to stream in full now on Apple TV+
