Our three resident del Luna hoteliers stand in front of the tunnel, pondering the return of Man-wol. Bartender Kim regrets not properly bidding farewell, but Seo-hee says that it's for the best if Man-wol resolved her thousand-year-old grudge. Hyun-joong pouts and makes the two promise to tell each other when they're leaving. As for the fate of the hotel, rumor has it that Mago is preparing for a new owner.
Herbalist Mago brews up a concoction that will ripen by the next month and looks for the final ingredient — the moon flower — but she's run out. At the hotel, Reapers asks about this moon drink for the new owner, and Mago explains that the drink will ripen to be bitter if the new owner carries a deep resentment.
Mago reminisces on how Man-wol threatened to cut her tongue for the disgusting drink. Aha, so that alcohol was the moon drink! Mago continues her explanation, saying that whoever drinks this moon brew will transcend the limits of time. The Moon Tree will absorb anything that carries the energy of the living, and the remaining soul becomes the owner of the Moon Lodge.
Mago comments that they've run out of the moon flower for this brew, and the last time she saw this flower was at the hotel's location 200 years ago. Reaper offers to fetch this flower, but Mago has someone else in mind for this task.
Chan-sung finds Seo-hee in Man-wol's office, and she hands him a familiar vial: the medicine to return his vision to the living world. Man-wol had left this vial with trusty Seo-hee, asking her to give this to Chan-sung when he would no longer need to come to the hotel. Seo-hee shares her interpretation of this mandate, that Man-wol didn't want Chan-sung to remain at a hotel where she no longer exists.
In his imagination, Chan-sung sees Man-wol showing off her outfit for a foodie outing, Man-wol complaining about the dream service call requests, Man-wol promising him a long wealthy life and consequently scolding him for letting this get to his head. Chan-sung's eyes turn sad when he sees the empty desk, and he returns the vial to the box.
When Chan-sung exits the office, he finds Mago standing in the hallway. He urgently walks toward her and asks if Man-wol has returned. She shakes her head and says that she has a task for him: Go back to the Man-wol Lodge, the hotel from the Joseon period, and fetch the moon flower.
Chan-sung suspiciously asks why Mago is sending him instead of going herself. He asks if he'll see Man-wol from that time, and when Mago confirms this, he decides to go.
As Chan-sung approaches the Moon Tree, we hear Mago's instructions to go around the tree to find the entrance to the Man-wol Lodge. When he returns, he will come back around the tree. He is not to eat or drink anything from this time; if he does, he will never return.
Chan-sung sees the entrance to the Man-wol Lodge on the other side of the Moon Tree and walks into the Joseon period. He smiles when he spots Seo-hee assuaging guests and Bartender Kim shaking his head at the pots of Man-wol's alcohol.
Chan-sung finds the garden with the moon flower, and a familiar voice calls out to him as a stranger. It's Joseon Man-wol, and she demands to know who he is. She's surprised when Chan-sung knows her name, and she closely inspects Chan-sung before determining that he's here to collect her debt. Man-wol dismisses him and promise to repay her debt soon.
Before she walks away, Chan-sung tries to stop her, and she defensively rams him against the wall. Chan-sung says that he's from a faraway place and that she won't recognize him in this time. Man-wol realizes that Chan-sung can see spirits and asks how he gained this power.
They're interrupted by the shrill voice of Mago, and Man-wol hides behind her fan as she curses at this unwelcome guest. Chan-sung recognizes this voice, and when Man-wol learns about the Magos' favorable treatment of Chan-sung, she looks intrigued and offers him a drink.
Bartender Kim and Seo-hee prepare a meal for Chan-sung, and Chan-sung asks if they have a human manager of the lodge. Bartender Kim reports that their human lodgekeeper recently passed away, and he wonders if Chan-sung is the replacement sent by Mago. Chan-sung denies this and asks who Man-wol mistook him for. He learns that the debt collectors are gamblers, and his eyes widen when he realizes that Man-wol has squandered her money with this new gambling habit.
After the lodgekeeper passed away, Man-wol coped by gambling and used a gambler ghost to help her cheat. She enjoyed a winning streak until Mago found out, and since then, they've been punished with daily visits from Beggar Mago, who's been taking all of their money. Chan-sung notes that this period of the hotel is much worse than the modern hotel.
Man-wol appears, and Chan-sung confronts her about her gambling problem. She insists that it was for fun and that she'll quit once she earns back her losses, but Chan-sung sternly orders her to quit now. She argues that they need money to run the hotel, but Chan-sung already knows that this is a lie. Man-wol looks impressed by Chan-sung's knowledge, as if she's met her match.
Next, Man-wol tries to enlist Chan-sung's help to get rid of Beggar Mago, but Chan-sung knows that they can't force a god to leave. Chan-sung offers a deal: He'll lend his expertise with Mago to lure her out of the lodge, and in exchange, Man-wol will quit gambling. Man-wol agrees and offers her wrist as collateral.
Chan-sung approaches Beggar Mago and introduces himself as a tasker sent by the eldest Mago sister. He politely requests that Beggar Mago leave the lodge and says that he doesn't want to see Man-wol experience more hardship. Beggar Mago doesn't intend to leave that easily and offers to play a game of his choice for this deal. Chan-sung agrees and suggests baduk.
As Beggar Mago and Chan-sung concentrate on their game of baduk, Man-wol anxiously asks Bartender Kim who's winning. Bartender Kim assesses that they're neck and neck, and Man-wol says that Chan-sung assured confidence with his brains, since he went to a prestigious place called Harvard (ha). Chan-sung makes his final move, and Beggar Mago frowns in frustration at her loss. She leaves the premises, per their agreement, and Man-wol squees in delight.
Later that night, Chan-sung makes Man-wol write a contract that she'll never gamble again. He then nags her to sell the extra horses to pay off the debt and gives her no room for excuses, knowing that she'll try to justify keeping the horses to build a pretty stable. He threatens to invite back Beggar Mago, and Man-wol reluctantly agrees to his terms.
Chan-sung tells Man-wol to find other hobbies to keep her occupied and draws a map of Korea for her. He identifies places on the map — Jeonju for bibimbap, Pohang for dried herring in the winter, Pyongyang naengmyeon — and Man-wol wonders if this will be a more entertaining hobby than gambling. Chan-sung assures her that it will be fun, enough to keep her occupied for the next 200 years.
Man-wol asks if he's visited all these places, and Chan-sung confirms that he's eaten all these foods with someone. She asks him to stay, to experience this new hobby with her and to be the new lodgekeeper. She offers him a drink, and Chan-sung remembers Mago's warning not to eat or drink anything, lest he get stuck in this period.
Chan-sung looks tempted and says that he could be with Man-wol without worrying that she'll disappear. But he puts the glass down and tells Joseon Man-wol that he needs to return to where he came from because he's waiting for someone, a person he loves very much. Aww. Man-wol regrets this missed opportunity, and he acknowledges that he may regret this decision later.
Chan-sung goes to the garden to collect the moon flowers, and Beggar Mago appears to tease him with his options to stay or go. She says that all memories of him in this Joseon period will be erased upon his return to the current time. But if he stays, he could remain as Man-wol's 85th human lodgekeeper. She playfully quips, "To return as someone who let go, or to remain as a passing being, that's your choice."
Even with the playful temptation of Beggar Mago, Chan-sung sticks to his decision to leave, and he takes one last glance at the Joseon Man-wol before exiting the lodge. Once he returns, we also see a car returning from the afterlife tunnel and back at the hotel platform. Could it be?!
Handing the moon flowers to Mago, Chan-sung says that he understands why she sent him on this mission. He realizes the strength and patience he needs to embody as he waits for Man-wol. Mago nods and tells him to first celebrate, as Man-wol has returned. Ah! Chan-sung immediately races for the platform.
Man-wol gets out of the car, and the rest of our resident hoteliers follow Chan-sung as he runs through the lobby to the platform. Chan-sung embraces Man-wol tightly, and she apologizes for being late. Then, the rest of the hoteliers run yelling for Man-wol and all join in the group hug, It's the cutest thing ever.
Through our hoteliers, we learn that Man-wol has lost some of her memories while crossing the bridge, and most of the lost memories are the oldest, most hurtful ones. Seo-hee ponders on the sadness and relief in having the most painful memories lost first.
Man-wol assures Chan-sung that she hasn't lost any memories of him, and as a test Chan-sung asks to choose between him and the red car. She laughs and obviously chooses him, and Chan-sung looks relieved. Then, he asks how many cars she has left, and Man-wol goes into a panic, wondering if Chan-sung sold more of her cars. Haha, she's back!
Then, Chan-sung mentions the names of the debt collectors from her Joseon days, and he finds some solace that she still remembers 200 years back. He pours her a drink and claims that he was regretting his decision to reject a drink with another pretty woman. Man-wol doesn't believe him and says that she's above jealousy (mmhmm). Then, she smacks him for trying to incite envy.
Chan-sung grabs her wrist and says that she must have kept her promise to quit gambling because her wrist is still intact. He shares that Mago sent him back to the Man-wol Lodge to collect the moon flowers and that he helped Man-wol out of debt while he was there. Man-wol realizes that Mago is brewing a new moon drink and remembers when she first had that bitter concoction.
At the hospital, the fake Ji Hyun-joong grandpa, Oh Tae-seok, watches over Hyun-mi and looks at an old photo of his younger self with the real Hyun-joong. We see that the two were best friends, and Yoo-na realizes that Tae-seok is a real friend, who is taking care of Hyun-mi for Hyun-joong. She shows Hyun-joong the articles of Tae-seok, who's done great work as a medical doctor with Hyun-joong's name.
Yoo-na thinks that Hyun-mi will live much longer with the help of this friend, but then, she receives a message about Hyun-mi in critical condition. Yoo-na rushes to the hospital, and Hyun-joong watches over his sister as the medical team saves Hyun-mi through another critical moment. Hyun-joong looks at his friend and says, "Hyun-mi is safe again, and you must be disappointed." Huh?
Grandpa Tae-seok exits the hospital room and finds Yoo-na waiting there. He asks if she took the photo of him with Hyung-joong, and she denies this. She requests that he keep Hyun-mi alive for a long time and says that Hyun-joong is always watching over them.
Before Yoo-na leaves, Tae-seok desperately asks Yoo-na if Hyun-joong is still alive. He wonders if Hyun-joong is making him keep Hyun-mi alive while he's actually still alive. Huh, curious.
Turns out, Hyun-joong took the photo to show off his golden days to the rest of the hotel staff. They notice the friend in the photo, and Hyun-joong says that this friend has been taking care of his sister in the hospital.
Bartender Kim and Seo-hee meet with Man-wol to request a special event for Hyun-joong when his sister visits the hotel. They want to give him the opportunity to spend more time with his sister, but Man-wol looks amused by their assumption that young innocent Hyun-joong is only waiting for his sister. She reminds them that Hyun-joong arrived at the hotel after dying of a gun wound.
As Man-wol cleans her shotgun, Chan-sung scolds her for the ominous reminder of Hyun-joong's death. She recalls shooting her gun at a perpetrator, puncturing him with the victim's bullet to haunt the him for life. Man-wol explains that Hyun-joong already punctured his enemy with his revenge bullet: Hyun-mi.
Hyun-joong left his sick younger sister with his enemy, and while it's true that Hyun-joong waited over 70 years for his sister, he also used his sister to torture his killer for over 70 years. Yoo-na arrives at the hotel and tells Hyun-joong that she's brought someone who wants to see him. It's Tae-seok, and Hyun-joong's smile immediately drops when he sees his friend.
Yoo-na tells Chan-sung that she wanted Hyun-joong to have an opportunity to reclaim his life while his friend is still alive, but Hyun-joong ran away immediately upon seeing his friend. She didn't realize that bringing Tae-seok would upset him. Chan-sung says that everything depends on Hyun-joong's choice.
Bartender Kim tells Chan-sung about Hyun-joong's story: Hyun-joong's parents died from a bombing during their escape, and he just barely saved his sister's life. His sister was badly injured, and he took a shortcut through the woods instead of following the masses of refugees. While collecting water in a river, he was held at gunpoint by a runaway soldier, and this soldier turned out to be Tae-seok.
Tae-seok hungrily ate the potatoes that Hyun-joong offered him, and Hyun-joong asked that his friend join them on their journey to Busan, where his uncle lived and where he could get help for injured Hyun-mi. But the friend suddenly turned on Hyun-joong, pointing his gun and ordering Hyun-joong to switch outfits, since a runaway soldier would be killed by either side of this war.
Once they switched clothes, Tae-seok tried to run off with Hyun-joong's belongings, but Hyun-joong desperately held on because all of Hyun-mi's medicine was in his sack. During a tussle for the sack, Tae-seok accidentally fired his gun, fatally shooting Hyun-joong in the chest.
Waking up at the sound of the gunshot, Hyun-mi called out for her brother, blindly reaching out because of the bandages around her injured eyes. Shaken and frantic, Tae-seok apologized to Hyun-joong and tried to run away, but Hyun-joong grabbed his friend with his last ounce of strength, begging him to take Hyun-mi. Hyun-joong just barely saw his friend carrying his sister before dying.
The uncle's family recognized Hyun-mi when they arrived in Busan, and they assumed that the boy carrying her was Hyun-joong. Ever since then, Tae-seok has been living as Ji Hyun-joong. Seo-hee comments that behind his cheerful demeanor, Hyun-joong must have carried a lot of resentment.
Man-wol finds Hyun-joong crouching at the foot of the Moon Tree and insults this image of a sad puppy under this gloomy tree, which is her way of acknowledging his sadness. She sits down next to him, and he cries as he admits his anger toward Tae-seok, who's living out a life that he would have had. He refuses to forgive his friend, and Man-wol sympathizes with this resentment.
But Man-wol also encourages him to listen to Tae-seok. She shares that listening to the other side helped her absolve her resentment and allowed her to let go of her enemy. Hyun-joong accuses Man-wol of still remembering the firefly when she claimed otherwise, and she scolds him to mind his own memories.
Man-wol says that Yoo-na's efforts will be for naught and gets up to send Tae-seok away, but Hyun-joong grabs the end of her skirt. She advises Hyun-joong to meet with Tae-seok, if not for his own resolution, then to acknowledge Yoo-na's sincere effort to help the person she likes.
In the lobby, Yoo-na tells Tae-seok that his presence only deepened Hyun-joong's pain and asks him to leave. Tae-seok offers the school uniform to Yoo-na, and she comments on how Hyun-joong loved school. Then, the elevator doors open, and Chan-sung invites Tae-seok to meet with Hyun-joong. Yoo-na looks surprised, and Chan-sung gives her the slightest smile of encouragement.
Seo-hee escorts Tae-seok to the room where Hyun-joong is waiting, and Tae-seok enters an old classroom. Hyun-joong tells Tae-seok that he's been watching over his old friend, and we see old Tae-seok turn into his younger form in the hotel room.
At the bar, Man-wol asks Chan-sung why he isn't worried about putting Hyun-joong in the same room with his enemy without any supervision. Chan-sung knows that Hyun-joong is kind and that watching his friend care for Hyun-mi all these years would have alleviated some of the grudge.
Man-wol reveals her plans to use Hyun-joong's kindness and charge Tae-seok an expensive fee for this visit. She intends to use this money on a special event for Hyun-joong. In her meeting with Tae-seok, she notes his history of generous donations and asks him to make one more to the prestigious school that Hyun-joong attended.
The school hosts a ceremony at the request of their generous donor, Doctor Ji Hyun-joong, to present honorary degree to the real Ji Hyun-joong in the middle of the night. Chan-sung explains to the principal that nighttime is better for their guests.
Hyun-joong arrives with the Man-wol and the rest of our resident staff, but those are the few that are visible to the human eye. Chan-sung comments that a large crowd showed up, and we see the mass of the hotel guests in the auditorium. Reaper offered his bus to lug the hotel guests there to celebrate Hyun-joong's graduation.
Upon receiving his honorary degree, Hyun-joong looks to the crowd with the biggest smile, and everyone applauds his achievement. Man-wol smiles proudly as she claps, and even Reaper shows a rare smile.
The hotel staff pile into Sanchez's pizza shop to celebrate the graduation, but only Man-wol and the long-time resident staff are visible to Sanchez. Chan-sung explains that the visible staff have the ability to appear in the living world because of their long residency at the hotel.
Creeped out by the idea of ghosts eating at his shop, Sanchez takes swigs of his wine, and Chan-sung warns him not to get too drunk, as ghosts can slip into human bodies when they're not sober. Chan-sung points to an empty chair in the corner and says that one particular ghost has been eyeing Sanchez, to which Sanchez comments that ghosts must like handsome people. Heh.
After the celebratory dinner, Sanchez jumps at the sight of an elderly woman crossing the street, convinced that it's a ghost. But Chan-sung assures him that this person his human, showing him (PPL) dashboard video evidence. Chan-sung tells Sanchez not too be so afraid, since ghosts were once human like themselves, but Sanchez insists that his fear is normal.
Sanchez worries about Chan-sung normalcy with the spirit world, but Chan-sung assures him that all of these ghosts will soon move on to the afterlife, Man-wol included. The reality of Man-wol's eventual fate seems to hit Chan-sung again, and Sanchez seems to sense this impending heartbreak.
Seo-hee tells Man-wol that she offered the ghost vision medicine to Chan-sung, but he returned it to the box. While Chan-sung trusted that Man-wol would return, Seo-hee admits that she was relieved to hear that Man-wol was able to cross over to the afterlife.
Man-wol reveals that she isn't tied to the Moon Tree anymore and that Mago is preparing for the heir to the hotel. It's an unspoken understanding between Man-wol and Chan-sung, but this is news to Seo-hee. Man-wol hopes to see Seo-hee, Bartender Kim, and Hyun-joong off before she passes on the hotel, but she isn't sure if she has enough time.
Seo-hee runs into Chan-sung, who updates her on the pregnant pharmacist, the woman carrying the child of Seo-hee's enemy family line. He asks if she'll remain in the living world if this child is a son who can carry the family name, and Seo-hee knows that he's worried that she'll linger long after Man-wol and the hotel disappear.
Seo-hee tells Chan-sung that Man-wol returned to the living world because of Chan-sung and echoes a piece of advice that Mago once shared: "It takes more heart to let go than to hold on." The image of the red string being snipped by the bride letting go of her lover flashes through Chan-sung's mind.
Chan-sung finds Man-wol hauling two heavy suitcases to her office, and he opens them to find an old camera. Man-wol explains that all the pictures on the wall were taken by the manager at the time. She runs through all the photos and memories of the managers associated with each phase of the hotel.
Man-wol tries to incite a jealous response from Chan-sung by reminiscing about a handsome manager, but Chan-sung doesn't believe her. He heard from Bartender Kim that Chan-sung is the most handsome manager they've had and that Man-wol fell for him purely on his looks. Heh.
Chan-sung asks why Man-wol didn't take photos with these managers, and Man-wol responds that these transient lives passing through the hotel had no significance to her then. But now, she wishes she had a record of these seemingly insignificant lives. Chan-sung offers to fix that now and suggests that Man-wol take photos with her long-time staff.
Getting ready for the photo, Man-wol orders Hyun-joong to keep his mouth closed and Bartender Kim to keep his eyes open, but they epically fail when Chan-sung takes the photo. They do get some nice and adorable photos, with the whole staff, with our three hotel musketeers, and with Chan-sung and Man-wol.
Man-wol sits on the camera suitcase and (first cutely and then sternly) orders Chan-sung to carry her off. He initially refuses and tells Man-wol to carry the suitcase herself, but then he swoops in and carries her. She points to the bedroom, and Chan-sung twirls her around before landing her on the couch. Man-wol pouts angrily, and Chan-sung tells her to get ready to eat jjajangmyeon. Womp womp.
Hyun-joong admires the staff photo with Yoo-na and tells her that they wanted to take some final photos before the hotel closes. Yoo-na looks surprised, and Hyun-joong explains that Mago is preparing for a new hotel owner, and Hotel del Luna will end, along with its staff.
Yoo-na complains to Bartender Kim that the hotel can't close and asks how she can meet Mago. Bartender Kim says that Chan-sung was granted entry to the Mago's herbal pharmacy and suggests that Yoo-na ask him. Yoo-na snoops around Chan-sung's office and finds the business card with the pharmacy information.
Mi-ra finally moves out of Sanchez's house to move in with Young-soo. Though Mi-ra is terrible at cleaning, Young-soo says that Mi-ra makes up for it with her great cooking, which is actually her parents' cooking. Turns out, Mi-ra's parents run a kimchi factory, and Young-soo is amazed that he (Sanchez: "and everyone else") grew up with Mi-ra's parents' kimchi. Sanchez holds his tongue and decides to tolerate the couple until Mi-ra officially moves out.
Bartender Kim serves two writer ghosts, one of which died just before releasing his new novel about a Joseon scholar. As the writer shares the storyline, Bartender Kim freezes at the eerie similarity between the main character's story and his story: a nameless scholar whose first place in the civil examination was revoked because his vulgar writing was discovered.
Upon hearing about the novel about this pervert scholar, Bartender Kim's hands begin to tremble. The writer reveals that the name of this scholar was Kim Shi-ik, and Bartender Kim overflows the cup with his pour. The writer hopes that his work will be published posthumously, but Bartender Kim tears up as he recalls the shame in his past.
Yoo-na arrives at the pharmacy and eyes the brewing moon drink. At the Moon Tree, Seo-hee comments that the tree has returned to its original state, but Man-wol disagrees. She says that the tree is different now because it has experienced time again, having grown leaves, bloomed flowers, and withered its petals.
Seo-hee asks if Man-wol wants the tree to grow and bloom again, but Man-wol knows that this tree is now dead. For the tree to experience time again, she'll need to cross over. Then, Yoo-na interrupts the conversation, running in with a bottle. She admits that she stole the moon drink from Mago and hands it to Man-wol, begging her to stay at the hotel.
Mago tells Chan-sung that Yoo-na stole the moon drink, and Chan-sung knows that Yoo-na's intentions were pure — to stop the hotel from disappearing and Hyun-joong from leaving. Mago presumes that she gave the drink to Man-wol, which would extend the life of the hotel and allow her to stay with Chan-sung.
Chan-sung asks Mago if she will stop Man-wol from making this choice, since she wanted to an amicable send-off for Man-wol. But Mago turns the question on him: What will he do if she doesn't stop Man-wol?
When Chan-sung arrives at the hotel, Seo-hee urgently notifies him of Yoo-na's theft and directs him to find Man-wol at the sky lounge. Chan-sung finds Man-wol watching the full moon with the moon drink bottle in her hands. He approaches Man-wol, and she tells him that the first time she drank the moon drink was during a full moon as well. She asks Chan-sung if she should drink this again.
Chan-sung tells Man-wol about his brief visit to the Joseon lodge, where he was tempted to accept the drink from Joseon Man-wol and remain by Man-wol's side. If he had remained there, he may have become the 85th manager, who drew the picture of Man-wol in front of the lodge. "But as I hung up our photo, I decided that I would remain as the 99th manager, the last one. I won't let a meaningless 100th time pass for you."
Chan-sung tells her not to consume the moon drink, and Man-wol smiles in relief because she knew that he would say this. She unbottles the drink, pours it over the ledge, and drops the bottle with a look of loss. Man-wol looks to Chan-sung and says, "Thank you, Gu Chan-sung. I love you." She reaches for his hand, and he takes it.
Chan-sung responds, "I love you." They look at each other lovingly and watch the bright full moon together.