After getting kicked out of Daegil's group, Seolhwa gets into trouble after she runs into her own Sadangpae group. Taeha hides in the house of his former boss General Shin because Hyewon is injured.
Daegil, Taeha, Cheolung, Baekho, and Yunji cross each other in downtown Chungju. Amidst the Chaos, Daegil catches a glimpse of Hyewon and gets stabbed by Cheolung while in a state of shock.
Hyewon a former slave tries to leave Taeha when she learns that the slave chasers are after him. Daegil studies the records and goes to Chungju because that's where Taeha's teacher Im Yeongho resides.
Taeha's teacher Im Yeongho waits for Taeha as he gives an order to Jo, who is his confidant. Hanseok, who was enticed by Lee Gyeongsik to betray Taeha, is now watching the royal grandson in Jeju as a guard.
While trying to save Kang Chi, Yeo Wool is shot by Seo-bwagwan. Yi Sun Shin arrests Jo Gwan Woong for leaking military secrets. As Yeo Wool dies from the gunshot, Kang Chi promises they will meet again.
Afraid of losing Yeo Wool, Kang Chi breaks up with her. She holds onto him, saying that losing him is what she fears most. Upset by the breakup, Yeo Wool goes out to clear her head and is attacked by a mysterious figure.
Kang Chi visits Monk So Jung, saying he wants to find the Gu Family Book so he can grow old with Yeo Wool. So Jung reveals their fate: one of them must die. Kang Chi is shocked. Meanwhile, Tae Seo is captured and taken to Jo Gwan Woong.
Gu Wol Ryung, unable to remember his past, attacks Kang Chi. Ja Hong Myung is tormented as she watches the fight between her half-beast son and the divine beast Wol Ryung. Later, Ja Hong Myung takes refuge at the school and meets Yi Sun Shin.
Gu Wol Ryung suffers as a thousand-year demon. Jo Gwan Woong tells him Seo Hwa is the cause of all his misery and proposes a deal. Meanwhile, Dam Pyung Joon tells Kang Chi to remove his bracelet and defeat him in a real sword fight.
Ja Hong Myung is shocked to realize Kang Chi is her son. However, despite Jo Gwan Woong's persistent questioning, she pretends not to know Kang Chi. Meanwhile, Yeo Wool seeks out Bong Chool to find a way to rescue Kang Chi.
Kang Chi and Yeo Wool enjoy the lantern festival. However, when a disciple is found dead with his liver eaten, Kang Chi falls under deeper suspicion. Tae Seo returns to the inn and tells Jo Gwan Woong about Yi Sun Shin's plan to build a new 'ironclad' ship.
Yeo Wool is put in charge of Kang Chi's discipline at the school. Despite their bickering, they grow closer and go to see the lantern festival. Meanwhile, unusual corpses are found in the forest, and the school's disciples begin to suspect Kang Chi.
To save Chung Jo, Tae Seo reveals Kang Chi's location to Jo Gwan Woong. Tae Seo attempts to behead Kang Chi himself and cuts off his prayer bead bracelet. Kang Chi transforms into his beast form in front of Tae Seo and Chung Jo. Seo-bwagwan, sensing Kang Chi is Wol Ryung and Seo Hwa's son, reports this to Jo Gwan Woong.
Kang Chi is asked by Tae Seo to rescue Chung Jo. He worries about how Chung Jo will react to his half-beast nature. Yeo Wool comforts him, saying he is still Choi Kang Chi, regardless of his appearance. Meanwhile, the Hundred Year Inn staff hear that Chung Jo is to spend the night with Jo Gwan Woong.
Kang Chi and Yeo Wool are trapped in the room where the silver chest is hidden. Seo-bwagwan grows suspicious of the wall hidden behind a scroll. Meanwhile, seeing Yeo Wool's scar, Kang Chi remembers his childhood encounter with her.
Dam Pyung Joon accepts Kang Chi and Tae Seo into the Mu Hyung Do Gwan (martial arts school), and Kang Chi strives to become a formal disciple. Jo Gwan Woong, suspicious of the Hundred Year Inn's asset list, searches for a secret vault. Meanwhile, Yi Sun Shin and Dam Pyung Joon plot to retrieve 5,000 nyang of silver without Gwan Woong's knowledge.
Jo Gwan Woong, having framed Kang Chi for murder, orders his execution. At that moment, Yi Sun Shin appears, demands Kang Chi's release, and declares the punishment unjust.
Following Buddhist Monk So Jung's advice, Park Mu Sol adopts and raises Kang Chi. Afterward, he succeeds in all his endeavors, building the Hundred Year Inn, the best in the south. Now an adult, Kang Chi causes trouble while trying to stop the marriage of his first love, Chung Jo.
Having given his heart to Seo Hwa, Gu Wol Ryung wishes to give up his immortal life to become human. He seeks to obtain the Gu Family Book by observing three taboos. Wol Ryung and Seo Hwa hold their own wedding and spend happy days in the Moonlight Garden, but Jo Gwan Woong remains relentless in his search for the missing Seo Hwa.
In the Moonlight Garden, rumored to be home to ancient mountain spirits, the guardian god of Jiri Mountain, Gu Wol Ryung, roams the human world. When Yoon Cham-pan is falsely accused of treason and executed, his daughter, Seo Hwa, is sold off as a gisaeng.