We flashback to six months prior when Tae-seok meets Chairman Choi for dinner. They’re excited to receive government approval for Next as an ADHD medication. Tae-seok hasn’t taken Next, but Chairman Choi and some of his associates have already been popping it for concentration boosts.
Shortly after his wife arrives, Tae-seok excuses himself to take a phone call and learns about Next’s strange biting side effect. His only concern is that this doesn’t get out, so he orders the patient be compensated and kept quiet.
Tae-seok hears a thud and goes back inside the dining room. He’s frozen in horror to see his wife lying bloody on the floor with Chairman Choi biting her neck.
Now, Ji-soo informs him the prime minister is asking to meet. Outside, Ji-soo asks where the refrigerator trucks are being taken. “The landfill,” Tae-seok replies. They need the space.
He knows Ji-soo doesn’t understand, but he’s had to make hard decisions based on what will cause the least damage. She’ll need to decide how much blood she’s willing to get on her hands soon, too.
Tae-seok asks about treatment progress. Ji-soo reports that all the patients injected with the treatment died. He orders her to keep trying while he stalls for more time.
At the apartment complex, Yi-hyun holds another meeting, although few show. Hak-je wants to break out since the authorities aren’t coming to help them, but Yi-hyun argues it won’t work. When Hae-sung again starts questioning whether the lower-class residents are telling the truth (none of the other rich residents came), Sae-bom quips he could go out and see for himself.
After the meeting, Sae-bom worries that the zombies will find some way inside. They could break through the doors or … she suddenly realizes they haven’t secured the rooftop, so she and Yi-hyun rush upstairs.
They don’t find any zombies, but Andrew is there, unflappable as always. Yi-hyun remarks on his calmness, but Andrew is just happy no one is treating him like he’s weird. He leaves them alone to enjoy the fresh air.
Sae-bom gets introspective and regrets not visiting her mom when she had the chance – she put it off because it was uncomfortable. When she worries about the infected and whether everyone will be okay, Yi-hyun says they just need to focus on staying safe.
Sae-bom chides him for the very unsafe act of touching that blood and risking himself. Yi-hyun wonders if putting it on Joo-hyung was fine then. Sae-bom grumbles it’s not like he made Joo-hyung eat it.
Upstairs, Young-ok is a mess. Woo-chang tries to calm her and suggests they give up on this place. That makes Young-ok the opposite of calm. If they leave and start over somewhere else, they won’t make any money.
What does ease her mind is thinking of all the improvements and repairs they can take charge of at the complex once the lockdown is lifted. Young-ok decides she needs to ingratiate herself with popular residents to secure her place as the resident representative.
She marches over to Yi-hyun and Sae-bom’s to apologize for locking them out, but she undercuts it by saying they really should’ve explained properly that they weren’t infected. Sae-bom invites her in anyway.
Young-ok’s attempt to win over Seo-yoon doesn’t go so well, so she turns her attention to Sae-bom. She reminisces about young married life and asks how Sae-bom and Yi-hyun met. Young-ok spots the picture on the wall and starts to smile, but then looks aghast to see the teenaged Sae-bom in handcuffs. Ha.
Seo-yoon whispers to Sae-bom that she doesn’t trust that ajumma. Sae-bom teaches her the adage to keep your friends close and your enemies closer.
In the gym, Yi-hyun and Jung-kook commiserate over Young-ok’s nonsense. Yi-hyun doesn’t get the big deal with the whole resident rep thing until Jung-kook explains the rep signs off on all contracts regarding the building and property. “It’s all money.”
Yi-hyun goes into the gym office to talk to Seung-beom who’s tired of being handcuffed and stuck in the room. Yi-hyun promises to let him have free reign of the gym if he’s still showing no symptoms in a couple days.
In 601, Joo-hyung viciously scrubs his face and checks for signs of infection while vowing to kill Yi-hyun. Sang-hee is for some reason still staying in his apartment, but she’s at least keeping the golf club with her for protection.
Joo-hyung questions her about whether she ever saw Min-ji taking medication and learns that she sometimes took something she got from the gym. When he leaves, Sang-hee begins frantically searching the apartment again. (What is she looking for?)
Joo-hyung heads down to the gym for a chat with Seung-beom. He says he’s grateful Seung-beom sold those drugs to Min-ji and asks if he can buy some too. When Seung-beom insists it wasn’t him, Joo-hyung threatens to get him kicked out and even starts throwing (non-dangerous) things at him. Yi-hyun watches from outside the door.
Meanwhile, the infected resident from the other building contacts Hae-sung after seeing his ad. He repeats the lie that they sequestered their few infected in the library, claiming it’s not that serious. The resident convinces Hae-sung to meet him in the basement garage for a legal consultation, but Hae-sung keeps it a secret from his wife.
So-yoon is no idiot, though, and checks the video intercom call log. She replays Hae-sung’s conversation with the resident and immediately goes to the resident cop couple. Sae-bom answers the door and moments later, she’s heading downstairs with her bat.
Back in the gym, it’s safe to say things have escalated. Yi-hyun strolls in casually while Joo-hyung screams and tries to escape from the entirely turned Seung-beom’s grasp. Ah, so he is infected. Joo-hyung begs Yi-hyun to save him, but Yi-hyun argues the world would be better off with him gone.
Elsewhere, Hae-sung goes to the basement where the infected resident stares longingly at his neck and entices him outside by saying there’s internet. (I don’t know why this cracked me up so much.) Back in the gym, Yi-hyun relents and saves the undeserving Joo-hyung.
Yi-hyun warns him to keep quiet about Seung-beom or else he’ll show everyone footage of him being attacked. Joo-hyung doesn’t get why he’s hiding that Seung-beom is infected. “Because he’s a person,” Yi-hyun reasons. Behind him, Joo-hyung surreptitiously grabs a weight.
Downstairs, Sae-bom arrives just as Hae-sung stupidly begins opening the door. She barely manages to get it shut and lock it again. The resident struggles not to turn and shuffles away. Hae-sung, of course, doesn’t believe he was in danger and is irritated Sae-bom (and So-yoon) lost him a client.
In the gym, Yi-hyun easily knocks Joo-hyung down and wonders if he really should just let Seung-beom have him. Joo-hyung hears footsteps outside and makes a run for it. Unlucky for him, it’s Sae-bom whose response to his claim that her husband is crazy is to knee him in the stomach.
When Hae-sung and So-yoon walk up, Joo-hyung declares Yi-hyun tried to kill him with “that beast.” He runs off while they go into the gym to investigate and find Zombie Seung-beom. So much for keeping it a secret. They go to Young-ok about it, and she pretends to have no idea Seung-beom has been kept in the gym.
Once he returns to normal, Seung-beom finally cops to taking Next twice. Yi-hyun advises him to keep rigid control of himself – the more he turns, the harder it’ll be to return to normal. Seung-beom confesses that he told Joo-hyung there are pills in his car.
Later, Sae-bom tells Yi-hyun there’ll be vote tomorrow to decide if Seung-beom gets to stay. Sae-bom hesitantly asks if what Joo-hyung said about Yi-hyun trying to kill him is true. Yi-hyun assures her he only scared him a little, which puts her mind at ease.
He suggests they use the good cop, bad cop play; he’ll be the bad cop. Sae-bom agrees to the strategy but says she’ll take the bad cop role. Yi-hyun should be the nice one.
Meanwhile, Hae-sung goes around campaigning for Seung-beom’s expulsion. It’s not a hard sell since he has video evidence to scare everyone with. When he gets to 601, he casually offers their spare room to Sang-hee. She doesn’t accept, but she does give him a grateful hug that feels quite calculated.
While Sung-shil nervously checks herself for signs of Lytta, Sae-bom tries to convince Se-hoon to leave his apartment to vote in Seung-beom’s favor. Se-hoon replies he plans to stay in his apartment until lockdown is over.
Over a drink with Yi-hyun that night, Sae-bom says she always regrets not doing her best in any situation. This time, she’s determined to face things head on and have no regrets. In the garage, Joo-hyung breaks into Seung-beom’s car and steals the remaining Next pills. (Can this dude chill with the nefarious scheming?)
The next day, everyone heads to the gym for the vote. Dong-hyun uses Sung-shil’s phone to record as Hae-sung explains why the law is on their side for exiling Seung-beom. When he plays the video, Sae-bom cuts in to ask if anyone got COVID.
She likens the two situations, reminding everyone that a virus doesn’t discriminate. If they start throwing people out, where does it end? What happens when it’s your family?
Hae-sung doesn’t like this line of reasoning and jumps in to hold the vote. When no one votes to throw Seung-beom out, Hae-sung clarifies they could keep him on the roof or something – he just needs to be separated. Now people start raising their hands.
It ends up with a tie thanks to his wife So-yoon voting for Seung-beom to stay. Oh, and the fact that he doesn’t count Seo-yoon’s vote. And then, in strides the tiebreaker Se-hoon decked out in his infection-proof suit. He formally announces his vote not to throw Seung-beom out and leaves.
Young-ok hops up to say it’s better this way. She didn’t feel good about throwing someone out (says the woman who voted to do just that). Seung-beom glares when she addresses him to say it wasn’t personal.
With that out of the way, Sae-bom and Yi-hyun take over to discuss safety. Yi-hyun suggests monitoring Seung-beom in pairs. Everyone looks hesitant, but Hyun-kyung volunteers herself and her brother as the first pair.
Elsewhere, Tae-seok and Ji-soo pay Chairman Choi a visit. Time is running out for both Chairman Choi and Tae-seok’s wife – they only have about a month left. Chairman Choi brings up the recent restrictions on people entering regions with high infection rates, and then casually says he’ll no longer support quarantine areas.
He instructs Tae-seok to cut off electricity and stop providing food. Chairman Choi isn’t concerned with little things like death. He’s a bold-faced hypocrite who outright says that others who have tasted blood are a problem anyway. Of course, he’s different.
At home, Hae-sung continues to treat his wife like crap and berates her for not falling in line like a good secretary. He then sighs that he shouldn’t have married someone “uneducated.” Ooh, this man needs to go. So-yoon stands by her decision but blinks back tears.
In other news, Dong-hyun continues being a manbaby and refuses to give his mother back her phone. Looking through videos, he finds a video Sung-shil recorded of her wound. It’s not clear if he gets the import, but he hastily hides it when Bo-ram walks up.
Bo-ram lets him know she spotted his phone in front of the building. Dong-hyun offers her money to go get it for him. (I swear, these cowardly, selfish men are getting on my last nerve.)
Sae-bom walks back with Se-hoon who shares that he’s interested in the end of the world. That’s why he’s so into military supplies and the like – he’s stockpiling survival tools. He even invites her in to see his collection, which could be a friendly gesture or a serial killer line.
Downstairs, Young-ok stops by to see Seung-beom who’s still angry with her. She leaves a water bottle and tells him to drink if he can’t hold back anymore. Young-ok leaves after telling him to let her know if he needs anything. I can’t tell if she’s trying to help him or set him over the edge.
Young-ok runs into Yi-hyun as he leads Hyun-kyung and Soo-min to their shift. She says she was comforting Seung-beom as the resident rep, which Yi-hyun doesn’t buy. Yi-hyun goes in to talk to Seung-beom who finally gives up a name of a buyer: Se-hoon.
In the lobby, Dong-hyun waits at the open door while Bo-ram checks out front for his phone. She finds it, but before she can get back inside, the persistent resident who keeps trying to get in shows up. Bo-ram slowly backs toward the building.
Yi-hyun rushes home, but Sae-bom isn’t there. Seo-yoon tells him she went upstairs with Se-hoon. Yi-hyun grabs their trusty family bat and heads up.
In the gym, Hyun-kyung and Soo-min start fighting over money again. Hyun-kyung feels awkward with Seung-beom listening in, so she drags Soo-min into the hall. Oh, no.
She starts crying over how he got an inheritance and full ride to college, while she only got enough for one semester. Now he’s acting like he’s owed her money. They stop arguing when they hear a thud and creep over to check it out.
On the second floor, Bo-ram and Dong-hyun come running in and block the door. (They let the zombie in, didn’t they?) They yell for everyone to run as not one, but two zombies bust in. While Jung-kook and Woo-chang are pursued by the zombies, Soo-min unwisely opens the stairwell door on the first floor.
He announces there’s nothing there, so of course a zombie comes up from behind. Hyun-kyung watches in shock as the zombie bites her brother in the neck and drags him into the stairwell. She runs back into the gym, locking and barricading the doors. In the office, it looks like Seung-beom drank the water.
Upstairs, Yi-hyun bangs on Se-hoon’s door, yelling for Sae-bom. Se-hoon opens the door (chain still on) and says she’ll be out shortly. Yi-hyun wedges his bat in the open door and asks if Se-hoon took Next. He vows to kill him if he lays a finger on Sae-bom.