It's the year 1392, the first year off Yi Seong-gye's reign as KING TAEJO after overthrowing the Goryeo dynasty in 1988. Yi Bang-won (now also known as Prince Jeongan) arrives at the palace and refuses to leave despite being told the king isn't available. King Taejo deliberately lets Bang-won stand outside for several hours while he listens to now-prince Bang-seok, the youngest of his eight sons, recite his lessons.
Eventually Bang-won begins bellowing at the top of his lungs, but instead of letting him in, King Taejo steps outside and says that Bang-won has seen him, so now he may leave. Bang-won wants to discuss the fact that King Taejo will be choosing his successor soon, and he even deep-bows as he begs King Taejo to remember that only a legitimate son (from a first wife) can inherit the throne.
He's aware that King Taejo favors Bang-won, the son of his second wife Lady Kang (now QUEEN SINDEOK), and he accuses his father of letting himself be swayed by a woman. King Taejo basically tells him to mind his own business and goes back inside. He tells Bang-seok not to let Bang-won scare him, but Queen Sindeok notes that it's King Taejo who seems to be scared of Bang-won.
On his way out of the palace, Bang-won runs into Sun-ho, who now works as a royal inspector. Sun-ho politely asks Bang-won to wear his uniform when he visits the palace, but Bang-won just grumbles that illegitimate sons always cause problems. Sun-ho points out that the new laws allow illegitimate children to be treated equally, but Bang-won growls that that will change when he's king.
Keeping his composure, Sun-ho also asks Bang-won to dismount from his horse inside the palace. Bang-won turns a corner and sees his horse lying dead with its throat slit. Bang-won chuckles that Sun-ho's father would have killed the gatekeeper instead — he tells Sun-ho that he's different from his father, and that he can take that as a compliment.
Meanwhile, Hwi looks at the secret letter he found in his father's armor. He'd made a deal with Lady Seo to help him gather information on his Lord Nam-appointed target, Yi Bang-won, and in exchange she'd ordered him to stay away from Hee-jae so as not to risk putting her in danger. Several years later, he now has an entire wall papered with sketches, maps, and information on Bang-won and anyone else who might be important for his assignment… including Hee-jae.
His current target is General Jung Sa-jeong, Bang-won's closest adviser. Hwi tells Sun-ho that Grand General Jung is a scoundrel, the type of man who kills and rapes for fun. Sun-ho's job is to talk to Grand General Jung and win points with the king, then Sun-ho will kill him and win over Bang-won.
Grand General Jung frequents a particular gambling house, and Moon-bok pays one of the serving ladies to tell him how many men Grand General Jung has guarding him while he plays. Moon-bok is nervous about storming the place with so many armed men around until Hwi reminds him of the money that's inside, and he's all in. Ha, some things never change.
They muscle their way inside together and with Jung-beom's help, they fight anyone who doesn't run away. Grand General Jung is playing a high-stakes game in a private room, but the brawl doesn't strike him as unusual for a gambling house.
He continues the game against his bodyguard's advice, but his opponent growls that he's obviously a gambling addict, and HAHA, it's Chi-do! Chi-do takes care of Grand General Jung's bodyguard while the others clear out the main room, then they tie Grand General Jung to a post and leave him there for Sung-rok, who's still working as Sun-ho's right-hand man, to arrest.
Hwi's gang goes back to their home and count the money that Moon-bok squirreled out of the gambling house. Moon-bok jokes that he wants to get so rich he can make kimchi out of wild ginseng, and he says they should find Chi-do a nice lady. Chi-do says he's happier living with them, and they stare at him like he's lost his marbles, ha.
Hee-jae is still close to Queen Sindeok, as she once predicted. On the way to the palace and she gets wistful when she passes a kite seller, which reminds her of that one happy day she spent with Hwi. She was told that Hwi died on the battlefield, and his name was even on the list of the dead.
Hwi still has the cloth Hee-jae tied around his head when he was injured — he keeps it wrapped around his bow. He knows that Hee-jae believes him dead because he watches her, and he was there when she floated a lantern on the river in remembrance of him.
At the palace, Hee-jae is still frosty towards Sun-ho. The queen is concerned about the upcoming decision of crown prince, aware that the officials and princes will object if he chooses Bang-seok. Sun-ho proposes that they dig up dirt on the other princes to pressure the officials.
Hee-jae figures that King Taejo favors Bang-seok because the younger the crown prince is, the longer he gets to stay on the throne. She says that King Taejo isn't the only one who feels that way and, staring pointedly at Lord Nam, she warns Queen Sindeok to be wary of people who are nice to her. Lord Nam quips that Hee-jae is known as a minister in a dress, and Hee-jae fires back that Lord Nam is called a king in a gat.
Backing off, Lord Nam says that they need to act before Bang-won does. The king plans to abolish private armies as soon as Bang-seok is made crown prince, effectively stripping Bang-won and his brothers of their ability to fight, then, Lord Nam says, "We will kill them all."
He somehow makes it sound like a threat towards Hee-jae as well, and the queen sees the animosity between them. In private Hee-jae asks to participate in the tributary trade so that she can use the money to stop the officials. She's confident she can stop Bang-won too, as long as she can predict his actions.
Afterward, Sun-ho starts to apologize to Hee-jae for his father, but she says Lord Nam is right — the conflict won't end until one side is exterminated. Sun-ho asks what she means to buy with the money from the trade, and she says vaguely, "The kind of power that can get a mere inspector fired." He chuckles that he needs to get on her good side, but she says seriously that she doesn't want to lose anyone else she cares about.
She says that she knows Hwi died because of his father, not Sun-ho as he claims, and tells him to do what he feels is right. She asks hopefully about a rumor that some of the advance army came back from Liaodong, but Sun-ho shuts that down, insisting that nobody came back alive.
He joins Sung-rok, who has a very furious Grand General Jung tied up in a shed. Sun-ho brings up an incident in which Grand General Jung got drunk and killed a woman, yet he was never investigated because she was lowborn and it's not illegal, so they had to arrest him for gambling.
Grand General Jung is close to Bang-won and his brothers, so Sun-ho offers him a deal — write down everything he knows on them, and he won't die today. He does, though Sun-ho tells Sung-rok that it will only temporarily save his life, since Bang-won will kill him if he's not beheaded for gambling first.
Hwi keeps an eye on Yeon from a distance, and on the one day per month she's allowed to leave Lord Nam's house, he follows her to the marketplace. One of Lord Nam's men goes with her, but he barely pays attention, so Hwi is the only one who sees a pickpocket steal Yeon's money pouch.
He beats up the guy and gets the pouch back, and since Yeon's escort is nowhere to be seen, Hwi takes the pouch to her directly. He quickly slips away, but he goes right back to yell at her for not paying attention. HAHA, he can't help being the big brother.
Unfortunately, Yeon recognizes him from the time she saw him at Lord Nam's house. She tells him proudly that she never forgets anything (oof, Hwi's face), then she uses him as a model for some shoes she wants to buy Sun-ho for his birthday tomorrow.
Hwi tries to leave again, but he spots thug leader Ganggae approaching with his men. Ganggae runs the gambling house that Hwi and his friends trashed, and Hwi knows that he's coming for him. He yells at Yeon to run, forgetting himself and using her name.
He hugs Ganggae like they're friends and whispers that there are soldiers everywhere today, so they need to talk somewhere private. He successfully prevents Ganggae from seeing Yeon, but unfortunately, Lord Nam's man witnessed Hwi and Yeon together.
Hwi takes Ganggae to a little restaurant, and Ganggae tells his minion to chop off his head. When the man draws his sword, he takes an arrow to the knee… heh, Chi-do is there, and he calls out calmly that he has twelve more arrows. Ganggae sneers that Hwi only has one backup, until Jung-beom and Moon-bok wave at him from the next table and he wisely agrees to talk.
Hwi proposes they put an end to their fighting, and he pays Ganggae for the damage to the gambling house with a pile of furs. He wants to run the gambling house together, fifty-fifty, and Ganggae says he'll think about it.
Sun-ho gives Grand General Jung's notes on the princes to Lord Nam, but he'd refused to reveal any information on Bang-won, and Lord Nam snarls that Sun-ho's whole purpose is to bring down Bang-won. He's pleased to hear that Hwi has begun his plan, but he warns Sun-ho not to trust Hwi or he'll turn on them.
Having heard what happened in the market, Lord Nam asks if Hwi would risk his life for a sister who doesn't remember him — Sun-ho says he would, something Lord Nam can't understand. Lord Nam tells Sun-ho to get Hwi to cut off Yeon or do it himself, otherwise Lord Nam will.
Later that night, Hwi sneaks into Lord Nam's house to talk to Sun-ho about Yeon getting pickpocketed while her escort wasn't paying attention, but Sun-ho says that Hwi put her in more danger than the pickpocket. Hwi hides behind a screen when Yeon brings Sun-ho tea, accidentally overhearing their conversation.
Yeon calls out Sun-ho for always smiling around her, even when she knows he's not happy. She says he can cry to her since he has nobody else to cry to, and Sun-ho almost lets his smile slip before pulling it back up and cracking a joke. Yeon says she met someone in the market who knows her name, and Sun-ho promises to take her to the market again tomorrow.
When she leaves, Sun-ho tells Hwi to be in the market tomorrow at noon so that he can fix this mess: "Make sure she doesn't think of you again. It's the best you can do for her."
King Taejo calls Bang-won to the palace to discuss his behavior the other day. He lists the faults of Bang-won's older brothers (taken from Grand General Jung's notes), which consist of alcoholism, extreme incompetence, and flagrant carousing, among other things. All of this makes them unsuitable candidates for crown prince, and King Taejo asks Bang-won if he thinks he's capable.
In front of Queen Sindeok, Sun-ho, Hee-jae, and many courtiers, he says that he'll let Bang-won choose who becomes crown prince. Cornered and outmaneuvered, Bang-won is forced to name Bang-seok, and King Taejo grins triumphantly. When he leaves the palace, Bang-won growls that only two people know about his brother's alcohol problem… himself, and Grand General Jung.
Later, Sun-ho escorts Hee-jae home, and Hwa-wol meets them at the gates. As he's leaving, Grand General Jung passes by and they exchange glares. Grand General Jung asks his men who the women are, and he's told that Hee-jae is one of the queen's favorites so not to be messed with, but Hwa-wol is just a gisaeng.
Hwa-wol asks Hee-jae to visit Lady Seo, who seems to be getting sicker lately. Hee-jae asks about Hwi, but Hwa-wol says sadly that her inquiries haven't turned anything up. Hwa-wol heads back to Ihwaru with one of Grand General Jung's men tailing her.
Anxious to see Yeon again, Hwi primps for hours, suffering the teasing of his friends. Moon-bok asks if he has a hot date, but Hwi just says that this may be the last time he sees the lady so he wants to look nice.
When it's time for Yeon and Sun-ho to leave for the market, Sun-ho mentions the shoes he found waiting for him this morning, joking that he has an admirer. They run into Hwi "by accident," and awww, he looks so shy when Yeon notices how nicely he cleans up. She tells Sun-ho that Hwi is the man who helped her yesterday, and Hwi tries to work up the courage to say something to chase her off.
When Hwi hesitates for too long, Sun-ho realizes that he needs to step in. He tells Yeon that Hwi is a thug frequently covered in blood, who uses violence to solve his problems. He asks Hwi if he knows Yeon's name because he was planning to kidnap her for ransom.
Growing angry, Hwi snarls that it's Sun-ho and his father who threaten people and treat them like dogs. Yeon bristles at the way Hwi speaks of Lord Nam, and she snaps that someone like him can't speak to someone like Sun-ho that way. She storms off and Sun-ho follows her, leaving Hwi with tears streaming down his face.
Despite being cool in the moment, what he was forced to do upsets Sun-ho to the point that he loses his temper during archery practice. Lord Nam tells him that he did well severing the relationship (between Hwi and Yeon), and Sun-ho sneers that he had a good teacher.
Lord Nam asks if he still resents what happened with his mother, yelling that she killed herself because Sun-ho couldn't let her go. Sun-ho screams that he's wrong — she did it because Lord Nam stole him from his mother.
That evening, Grand General Jung visits Ihwaru, taking special interest in Hwa-wol. Hee-jae arrives to see Lady Seo, but when she enters the property, she finds people running around in fear and Hwa-wol bleeding heavily from a head wound. Grand General Jung drunkenly waves a bloody wooden club around, and he laughs uproariously when he sees Hee-jae.
He staggers over to Hee-jae and slurs that he might take her as his concubine, but she just spits that he's a drunken dog. Grand General Jung kicks her, and bodyguard Gyeol grips his sword while Hee-jae yells at him to do his job. But Grand General Jung throws his status as a founding contributor of the new nation around, daring anyone to come at him, and Gyeol chickens out.
Hee-jae grabs Gyeol's sword and points it at Grand General Jung. She's ready to take him on, but Lady Seo barks at her to stop and slaps her for daring to threaten Grand General Jung. Lady Seo apologizes profusely to Grand General Jung, and once he's gone, she calls for a doctor to treat Hwa-wol.
Hee-jae watches over Hwa-wol all night, and in the morning, Lady Seo asks to talk to her. She seems genuinely worried about Hee-jae, who apologizes for losing her temper. She says that her closeness with the queen made her forget her status, but Lady Seo says that she learned a valid lesson about recklessness.
With actual admiration in her eyes (maybe even love?), Lady Seo tells Hee-jae that at least she didn't let Grand General Jung intimidate her. She says she's relieved to know that Hee-jae can handle herself, but that it also worries her, then she starts gasping for air and leaves.
Bang-won sends Tae-ryong to hire someone to kill Grand General Jung. Tae-ryong approaches Ganggae for the job, instructing him to take only a few, dispensable men. Ganggae cackles that he has the perfect person in mind. He approaches Hwi and his men, piquing Hwi's interest by offering to pay him half to make the kill himself.
Grand General Jung is told that Bang-won wants to see him, and he's taken to Ihwaru. Not long after, Ganggae arrives with Hwi and several other assassins.
Meanwhile, Sung-rok reports to Sun-ho that Ganggae and Hwi are on the move. Sun-ho goes to see King Taejo and tells him that if Bang-won and Grand General Jung join forces, they'll jointly command a formidable private army. King Taejo notes that this wasn't in Lord Nam's report, and Sun-ho says that it's because he didn't tell his father. KY asks who else knows this, and Sun-ho says, "Now and for years to come, it will only be you." King Taejo asks what he should do with Grand General Jung, so King Taejo tells him that Grand General Jung will die tonight.
While Grand General Jung waits for what he thinks is a meeting with Bang-won, Ganggae and his men burst into Ihwaru and begin killing Grand General Jung's men. Hee-jae is there, and she runs to see what the commotion is about. She spots one fighter who seems familiar, but his face is covered with a mask.
Hwi fights his way to Grand General Jung, who grabs a sword to fight back. Within seconds, Hwi impales Grand General Jung on his sword, and as he's dying, Grand General Jung pulls off Hwi's mask. Hee-jae stares in shock at the face of the man she was told had died four years ago.
She breathes his name, and Hwi turns to look at her. After a long moment he tries to run, but Hee-jae grabs his hand and stops him. She refuses to let go, and Hwi turns to her again, tears welling up in both their eyes