Lieutenant Jung Tae-eul crosses through the portal with King Lee Gon to the Kingdom of Corea. She struggles to accept that there's a parallel universe and that Captain Jo Yeong isn't the Jo Eun-sup that she's known since she was three years old. She grabs a gun and points it directly at the king. Captain Jo immediately steps in front of it and grabs hold of the gun. All of the guards draw their guns and aim right at her. King Lee Gon tells her that everything is real so don't think about pulling the trigger to test it. Captain Jo demands she lets go of the gun unless she wants to get killed. With that, she lets go and Captain Jo realizes that she's the person from the name badge His Majesty has kept all these years.
Tae-eul slowly starts to wrap her head around the situation as she meets more people in the palace. They look just like the people she knows from the Republic of Korea but is completely different. Captain Jo approaches her for fingerprints to check her identity to which she happily complied stating that she understands how he's feeling because she went through the same thing. Captain Jo asks her if she's from a parallel universe and if she was the cause of His Majesty's scar on his shoulder. Tae-eul denies knowing about the scar because they're not close enough to see each other's backs.
King Lee Gon cooks a meal and delivers it to Tae-eul. Head Court Lady Noh enters the room to inform them that a bedroom has been prepared for Tae-eul. The bedroom is the furthest away from the king's bedroom. Head Court Lady Noh escorts her to the guest bedroom she'll be using for the night. It's rare for outsiders to ever spend the night in the palace so everything must be kept secret including all conversations with the king and information regarding the palace. Head Court Lady Noh warns Tae-eul that an existence that cannot be explained will only bring chaos and harm to the king. So she must not get curious about this world and avoid contact with others.
Later that night, King Lee Gon sneaks into Tae-eul's room. He brings her some alcohol per her request from earlier. She asks to see the ID badge, but he said he'll show her the next day otherwise she might leave immediately once she's seen it. King Lee Gon lays his head on her shoulder while they sit on the floor talking. She asks him to move and if he's ever dated before. He holds her head gently as he leans in and kisses her on the lips. He asks her if the kiss proved that he dated before or if he's dating now. She stares at him quietly without moving an inch.
The next morning King Lee Gon gives Tae-eul a royal guard uniform so she can attend his packed schedule. Captain Jo unwillingly becomes the messenger between the king and Tae-eul. He passes a message to Tae-eul from the king that he's helped her escape so she can go have fun until the evening. Tae-eul passes a thank you message back to the king and asks Captain Jo for some spending money.
Things start to sink in when Tae-eul asks random pedestrian questions regarding the king. She learns that the Kingdom of Corea has an extremely high GDP due to exporting rare-earth elements and that the king is a trillionaire from owning land that contains these minerals. Some criminals previously arrested by Captain Jo tell him that Tae-eul is Luna the woman in the rabbit suit they chased back at the rowing competition. She stole their boss' money and now he's in prison because of her.
Traitor Lee Lim reaches out to a poor pregnant lady living in what he describes as hell. He sent her pictures of a pregnant lady that looks just like her living luxuriously. If she chooses, she can become the granddaughter of the founder of a large pharmaceutical company that's married to the eldest son of a rich family. He explains to her that she is the woman in the photos, just in a different world. He's been choosing people and not a single one has turned down his offer to take over the better version of themselves. All she has to do is kill the other her and she can have everything. It turns out the woman Lee Lim is trying to replace is a close acquaintance of Prime Minister Koo Seo-ryung.
In the Republic of Korea, Kang Shin-jae was hoping to hang out with Tae-eul. He sends her a text to go play pool since they have the day off. He disappointingly checks his messages ever so often hoping for a response but doesn't hear from her. While out, he runs into his psychiatrist and chats with her for a bit over beers outside of a mart. She asks him if he still has recurring nightmares but he deflects the question since this isn't a therapy session.
While running around exploring, Tae-eul searches for familiar faces. She encounters some of her police team members at the police station, but they don't recognize her. She takes the CTX train (Corea's KTX) to Seoul in hopes of finding her father or mother. Unfortunately, she wasn't able to locate either of them. She tries to buy a ticket back to Busan but is short on money. Tae-eul calls the royal guards mainline seventeen times in hopes of reaching the king. The king eventually finds out and flies his helicopter straight to Seoul to get her. As she's standing there looking up at the helicopter, Captain Jo suddenly appears right next to her. He received orders from the king to keep her alive. Captain Jo questions her identity and why she went to the police station earlier.
King Lee Gon arrives and asks Tae-eul why she traveled to Seoul and who is Ahn Bong-hui. Tae-eul realizes that Captain Jo was following her and gave him a dirty look because he should've given her some money for the train if he was there. King Lee Gon wants to know who she's looking for in his world. She explains that she thought her mother might be alive in this world even though she'd be someone else but she didn't find her. King Lee Gon understood and let her know she could've just told him. He jokingly brings up that she's been curious about a lot of things. She didn't realize that her search engine didn't clear on his phone when she was searching for things like Lee Gon's ex-girlfriend and Prime Minister Koo.
Just then, Prime Minster Koo shows up. Captain Jo guesses that she must've gotten a report that the king's helicopter landed in Seoul. With her eyes never leaving Tae-eul, she tells the king that they're meeting at an unexpected hour, in an unexpected place, with an unexpected person. He responds that she's putting him in an awkward situation. Prime Minister Koo introduces herself to Tae-eul as she reaches her hand out for a handshake.