Instead of doing a magical Sailor Moon-like transformation every time Young-min takes over Seung-tak’s body, the narrative often relies on established mannerisms — namely, Young-min’s over-the-top cockiness and penchant for dramatic lab coat flipping — to reveal who’s in the driver’s seat. The personality switches cause the other ER doctors to scratch their heads, but luckily Seung-tak has Soo-jung to cover for him when people start asking questions.
She hasn’t outright confessed that she’s figured out Seung-tak has listed his body on ghost Airbnb for Young-min to inhabit whenever there’s a medical emergency, but it’s obvious she knows. Not only did she gleefully — no questions asked — agree to slap the ghost out of him whenever he’s acting weird, but she also explained away his behavior as being “normal” (for him). “Oh, he’s been like this since college,” she lies to their peers, claiming that he has a hidden surgical genius inside of him that only comes out to play when he feels like it.
Although true — just not in the way they think — the other doctors believe her lie. Given how well he hides his booksmarts behind his chaebol persona, it seems plausible to them that Seung-tak could also be a surgical savant.
It’s a theory that grows stronger after Seung-tak flexes his intelligence at the department conference, where the doctors and lawyers gather to discuss the timeline of Chairman JANG KWANG-DEOK’s (Lee Moon-soo) surgery. But the real agenda for the meeting is to point fingers until they identify the person who will take all the blame for administering the overdose of Heparin, which triggered the almost deadly medical emergency that landed Kwang-deok in a coma.
Doctor KIM JAE-WON (Ahn Tae-hwan) hesitates to admit that he asked Seung-tak, the chairman’s grandson, to administer the drug on his behalf, and a bored looking Seung-tak seems uninclined to confess. As the rest of the room goes tense, waiting on Jae-won to explain what happened next, the invisible Young-min yells at Seung-tak to take ownership for his mistake.
Seung-tak finally raises his hand and admits that Jae-won asked him to increase the dose of Heparin, and Seung-won gets a smarmy smile on his face. He’s pleased that his cousin is going to be blamed for Kwang-deok’s coma, but then Seung-tak adds that he did not follow through with Jae-won’s request. Everyone — Young-min included — assumes that he’s lying, and Seung-won and his fan club of lawyers are keen to catch Seung-tak in his lie and pin the blame on him.
Much to Seung-won’s dismay, though, a nurse steps up to corroborate Seung-tak’s story. After reviewing the patient’s chart and Young-min’s prescribed dosage of Heparin, Seung-tak deemed an increase of the drug to be dangerous. He left the patient as he was and instructed the nurse to relay the message to the other doctors. So, if Seung-tak didn’t administer the Heparin overdose, then who did?
As the doctors try to figure out the mystery among themselves, Young-min visits each of them and provides us with more insight into his team members. The more he reveals about his fellow doctors, the more we realize that Young-min actually cares for them. He struggles to imagine any of them putting a patient’s life at risk, so the outrage he feels when he discovers that Doctor AHN TAE-HYUN (Ko Sang-ho) conspired with Seung-won isn’t just on behalf of the patient. He feels genuine betrayal and anguish.
Tae-hyun was someone he mentored, and feeling responsible for his protege’s actions, Young-min apologizes to Kwang-deok. Kwang-deok is unfazed by the revelation that his son conspired with hospital staff to murder him. He already knew, and his acceptance of it is downright heartbreaking.
It is during this exchange that Young-min realizes that Kwang-deok is able to move around the baduk game pieces. He has a lot to learn about being a coma ghost, and so Young-min seeks out the three ghosts he’s been avoiding. They were the coma patients that he’d previously dismissed as lost causes, and he hopes they will forgive him and teach him everything that they know.
HWANG GUK-CHAN (Han Seung-hyun), CHOI HOON-GIL (Tan), and LIM BO-MI (Yoon So-hee) explain that ghosts and living people exist in two separate parallel universes. Inanimate objects bridge the divide, and objects that exist in the living world can be brought into the ghost world without any repercussions in the living world.
So, if Young-min wants an iced Americano or his tailored suits back, he needs to find them in the living world, touch them, and bring a copy of them into the ghost world. Ghosts can’t touch the living, though, so if Young-min wants to dish out physical punishment to Tae-hyun, he needs to do it while occupying Seung-tak’s body.
And so, Young-min hijacks Seung-tak’s body and sneaks into the on-call doctor’s room while Tae-hyun is sleeping. Acting like a full-blown creeper, he stands shadowed in the doorway and threatens Tae-hyun with nightmares every night until he confesses his wrongdoings.
Tae-hyun chases after him, but when he finds Seung-tak in the ER, Seung-tak plays dumb even though he’s clearly out of breath. (Yeah…maybe riding around the track at the gym on a motorized scooter instead of doing some actual cardio was a bad idea.) Seung-tak had the forethought to convince the security guard to delete the CCTV footage, but it’s not the first time he’s had to pull rank and get the incriminating evidence deleted. Young-min has been putting a lot of mileage on Seung-tak’s body lately.
At first, it started as a favor to reward Seung-tak for moving his body when Seung-won tried to remove his life support. With Young-min performing medical miracles in Seung-tak’s body, Seung-tak gained the respect of his peers and his grandfather’s approval. Young-min isn’t entirely altruistic, though, and he did make a selfish trip to his apartment, where — I’m pleased to report — he showed an appropriate level of concern for his missing sugar glider.
Se-jin catches him (as Seung-tak) with a suitcase full of his fancy clothes, and as she inspects the contents of the stolen wardrobe, we get a glimpse of her relationship with Young-min. He wasn’t always materialistic or a fashion snob. In fact, Se-jin was the one who encouraged him to buy new clothes and match his handsome face with an update to his wardrobe, which leads me to believe his current fashion addiction is a direct result of her abandoning him. After she left, he tried to become the man she wanted. My heart, y’all.
Unfortunately, Se-jin, who is now Young-min’s doctor, also has some bad news: Young-min’s brain activity has gotten worse. He’s dying. Young-min realizes jumping in and out of Seung-tak’s body is the cause of the decline. So, not only will he die if he’s knocked out of Young-min’s body while on a field trip outside the hospital, but repeated body possession will also slowly kill him. It’s too risky, and Young-min vows to quit inhabiting Seung-tak’s body. But we all know how hard it is to go cold-turkey when trying to quit a bad habit.
A patient arrives in the ER, and Seung-tak’s peers declare him — and his borrowed surgical skills — the dying man’s only hope. Seung-tak steps up, acting surprisingly more confident than usual. Perhaps he’s grown a bit too reliant on the ghost who has been performing surgeries on his behalf, which is unfortunate because Young-min has every intention of sitting this surgery out.
Once in the operating room, Young-min grows increasingly frustrated with Seung-tak’s insistence on performing the surgery. Seung-tak can’t even manage to hold the scalpel right, and Young-min barks instructions, which he knows Seung-tak cannot hear. But then — Oh my! — Seung-tak’s grip on the scalpel adjusts… as if he hears Young-min. Then, looking directly into Young-min’s eyes, he asks for help! Because — Oh snap! — he’s been able to see Young-min all along!
There have been clues, of course, like Seung-tak selecting a different soda to drink, but I assumed that the changes in Seung-tak were a side effect of being possessed, as though Seung-tak was absorbing some of Young-min’s personality traits and preferences. It seemed like a bit of a two-way street, too, since Young-min recited multiplication tables when he was frustrated at one point. But I guess when you hang out with someone long enough, their habits start to rub off on you — with or without body possession being involved.