King Lee Gon convinces Lieutenant Jung Tae-eul that there's a portal in the bamboo forest that leads back to his world. They get to the forest, but there's nothing there except for trees. He tells her it's just as he expected, the portal isn't opening because he came empty-handed. She mentioned that the DNA results get back tomorrow so they'll know who he is anyway. However, he informs her that he doesn't have any family alive with similar DNA since they passed away when he was young.
Detective Kang Shin-jae reminisces about the time he first met Jung Tae-eul. They were in high school and he joined her father's Taekwondo school. Eventually, he started instructing the students, but the kids disliked his tough approach and would go home crying. Jung Tae-eul's father gave him a police exam prep book in hopes that he'll stay on the right path in life. Just not as an instructor for kids at his school. While thinking about old times, he walks pass Maximus, King Lee Gon's white horse. He notices that the emblem on the harness matches a clue in their murder investigation.
King Lee Gon can't help but spend time with Jo Eun-sup despite Lieutenant Jung's attempt at interfering. He appoints him as Chief of the Royal Guards as the Unbreakable Sword of this world. Eun-sup calls him crazy and continues on his merry way. Being around Eun-sup really makes him miss his friend Captain Jo Yeong and Court Lady Noh who helped raise him.
Back in Corea, the word is starting to get out that the King is either missing or ill. The new employee at the Royal Public Affairs office, Myeong Seung-a, comes up with a plan to cloud the attention of the people. She goes through Captain Jo Yeong's phone for a good photo to use for a social media account she's planning to make for him. The people went crazy over the bromance of the Gon Jo couple.
Court Lady Noh reaches out to Captain Jo regarding the lady on the badge that the King keeps. He lets her know that he's already investigated her three years ago under His Majesty's orders, but found nothing. She doesn't exist in any database and the issue date is strange considering it was issued 2019 25 years ago.
Lieutenant Jung Tae-eul receives the DNA test results and there are no matches in any database. On top of that, Maximus is a rare horse breed that you can't find in Korea. She contacts King Lee Gon to go for chicken and beer before trying to wrap her head around the situation. While waiting for her to settle down, he learns about the art of mixing soju and beer. Although she doesn't believe that there's a parallel world, she can't help but ask him questions about it. Things don't add up no matter how she sees it.
Captain Jo Yeong remembers talking to King Lee Gon about Prince Buyeong performing the autopsy on the body they found in the past. It was determined that the fingerprints and DNA all matched with traitor Lee Lim. Although everything matched, King Lee Gon felt like it wasn't actually the traitor Lee Lim but a lookalike. The body must have been used by Lee Lim as a symbol that he's dead. The big question is what is this body that has identical DNA as Lee Lim and what was added to the traitor after it died. It seems that something was added to His Majesty.
King Lee Gon started having strange side effects while he was in the Republic of Korea. A large portion of his shoulder burned up one-night causing immense pain with a web-like marking. On a random day, everything around him froze when he was standing there talking to Lieutenant Jung. She didn't seem to notice anything although time had stopped.
Somehow Lee Lim has been getting updates about the King's actions throughout the years. He goes into a bookstore where his followers would drop by daily. He goes and meets with a large army of men that still kneels before him and calls him "Your Highness."
Lieutenant Jung and Detective Kang are out in the field working on a case. Suddenly, a group of men led by one of Detective Kang's old classmate appears. He sent the man to jail three years ago and now he's back for revenge. King Lee Gon appears to spectate the fight. As the two cops fight off about ten men, the boss approaches them with a knife. At that moment, King Lee Gon steps in to help. He knocks everyone out using his horsewhip and the three of them grab food after.
King Lee Gon goes to the bamboo forest with the flute. This time the portal opens up and he confirms that the flute allows the ability to go back and forth between the two worlds. King Lee Gon lets Lieutenant Jung know that he'll be leaving now. He's left the palace empty for too long and should return to his throne. While going to get Maximus, Detective Kang asks him what is the logo on his horse's harness. King Lee Gon tells him he must've been mistaken because that logo is used in a country in another world. After his goodbyes, King Lee Gon and Maximus ride back through the bamboo forest to enter the portal and get back to Corea.
