The episode starts with Naksu confessing to Jang Uk that she’s a soul shifter as her identified the blue marks in her eyes. Go Won comes there with the turtle and Jang Uk covers her eye from Go Won. He lies to Go Won that she was scared as a wraith attacked her. Ho Kyung asks Master Lee if what Seo Yul said was true and that Naksu’s soul would leave Bu Yeon’s body and she would ger her Bu Yeon back. Bu Yeon predicts that the mage hated Seol Ran which is who she got attacked as the body belongs to Jin’s family. She asks how did they come there and they say that it was her who summoned them with the jade. She couldn’t understand and asks Go Won why is he with Jang Uk. Go Won says that he has made ally with Jang Uk ditching Jin Mu.
He says about Jin Mu’s secret organization of soul shifters and he’s helping Jang Uk to destroy them. He’s pretending to be an ally with Jin Mu so that he would gather all the soul shifters so that Jang Uk could slay them. In the flashback Jang Uk asked Go Wo the real reason for ditching Jin Mu and he states his turtle as the reason. Jang Uk believes it while Go Won feels for his turtle. Go Won pretended to ally with Jin Mu to attack Jinyowon using the soul shifters which is why he couldn’t stop when she was sent inside Gwidu
Park Jin and Go Won all planned together to fool Jin Mu by pretending to send Jang Uk to the North Fortress. Go Won asked him whether he had issues with Bu Yeon and told that she already shared many things about him. He also told him that it was him who asked her to treat him the same way like she does. Jang Uk told whatever happened and Go Won predicts that her ex-lover may be married now. He advised him to win back Bu Yeon. They find Go Won’s turtle and the door for Gwidu opened and enter in as they got summoned by the jade. Bu Yeon believed that it was real Bu Yeon who opened the gate to save herself.
Master Lee says Ho Kyung that she used ice stone to revive her dead baby which originally belonged to Seol Ran. He doubts that Bu Yeon is actually Seol Ran but Ho Kyung doesn’t mind it. Go Won notices the red jade in Bu Yeon’s hand and asks about it. Bu Yeon says that it’s Jang Uk who gave it to her as he could see through its memories. Go Won talks about Mu Doek and how he fell in love with her. He also says that he was in immense pain when she died and the pains till continues. Bu Yeon says that she always wanted him to be ally with Jang Uk and asks him to move on after his pain is gone. She says that she Mu Doek wouldn’t like to see him in pain.
So Yul shows the potion So Yi to Master Heo who says that it’s a potion used to control soul shifter using a bell sound for them to run wild. He asks her assistant about it and he explained how So Yi used it on random people upon Jin Mu’s saying. He also reveals that she felt guilty as a girl from Sa Ri village also fell prey to the potion. Seo Yul and Park Jin interrogated the Queen about the same who revealed her intentions to soul shift to another beautiful body and is in support of Jin Mu.
They both gets angry hearing her and fought with her but she’s not ready to understand. Seo Yul understood that Nak Su is also the victim of the potion and says it to Park Jin. Jin says that it’s Jang Uk’s power that he struggles to handle and his burden would either increase or decrease depending upon the path he chooses. After lots of thinking, Jang Uk finally finds that Nak Su is Bu Yeon. Go Won leaves the turtle with Bu Yeon and takes his leave asking Bu Yeon to sort out his issues with Jang Uk. Bu Yeon realizes that Uk is turning blind eye to the fact that she’s soul shifter. They both decide to keep it for later as they have a big fight ahead them.
Park Jin sends Dang Gu to Jinyowon and Seo Yul to protect Cheonbugwan. They all were ready for the fight. Go Won sees all the soul shifters that Jin Mu has organized in his secret army. Jang Uk, Seo Yul and Park Jin enters the place and fights Jin Mu’s men. Go Won finally reveals the truth that he made ally with Jang Uk and ditched him who kept ordering him around like a servant. While the others are fighting outside , Jang Uk tries to enter the secret room breaking the barrier. He makes dimensions and goes in different appearance in different dimensions. Jin Mu finds himself alone when Jang Uk comes there.
While his other alters were fighting the soul shifter Jang Uk expresses how much he despises Jin Mu. He says that another person really wants to punish him and lets him go. He recalls Bu Yeon asking him to send Jin Mu to Gwidu for her to get her revenge. She lures him with another ice stone of the wraith and Jin Mu falls prey to her plan. Bu Yeon reveals herself to him and uses her powers to send the ice stone inside his body which would suck his energy to give a painful death to him and he would be locked up in Gwidu forever.
Park Jin tries making the King understand that the final attack was required to eb kept secret which is why they couldn’t inform him or Unanimous Assembly. He says all the soul shifters are dead. Queen learns from Yul’s Uncle that Jin Mu is dead and gets extremely angry as she can no more soul shift. She asks Uncle to find a way to meet Jin Mu. The turtle helps Bu Yeon find the plaque and goes disappearing into the sea. Master Lee reads about the turtle which posses the great energy of Black Tortoise.
Bu Yeon comes out of the Gwidu and Ho Kyung thinks that It’s Bu Yeon but she says she’s not. Yul says the truth about the bell potion to Bu Yeon to lessen her guilty but she’s not convinced. Jang Uk is ready to leave North Fortress and feels bad that he can’t attend Kim’s wedding. He wishes her all the good wishes on her big day. Yul says Jang Uk the truth about Nak Su soon leaving Bu Yeon’s body after her energy is drained. At Unanimous assembly Bu Yeon presents the plaque and says about killing Jin Mu with ice stone. The other members suggest to get her to remove the ice stone from Jang Uk’s body as there are no more soul shifters.
Queen and Uncle enter the Gwidu. Jang Uk comes alter and everyone confronts him about him turning blind eye to a soul shifter. Jang Uk meets Bu Yeon and they both hugs tightly. Seo Yul’s Uncle finds Jin Mu who’s half dead. Queen asks for Soul Ejector and it’s revealed that he ahs all the time kept it inside Queen. Queen final realizes that It’s Jin Mu who’s responsible for her condition. Jin Mu kills her and soul shifts with Uncle’s body. Uk and Yeon share a passionate kiss. Jin Mu comes to the court and it’s revealed that King is also his ally along with other Assembly members. Jang Uk comes to a place where three coffins are present.