Ah Ro watches as Ji-dwi meets with Queen Regent Jiso, and is shocked to hear him call her "Mother." The queen regent's bodyguard, Hyun Chu, finds Ah Ro accidentally eavesdropping and drags her off — she's doomed now that she knows Ji-dwi is really the king.
As Ban-ryu struggles to decide whether to follow Minister Park's orders to destroy the musical instruments, his father Ho Gong finds him and asks if the deed is done. He tells Ban-ryu that this is a test, and Ban-ryu asks if his father is that scared of Minister Park.
His father skirts the question, and simply says that everything they're doing is for Ban-ryu. Ban-ryu growls that he knows that, but he also doesn't believe that Ho Gong cares what he thinks.
Troublemaker Kang Sung sneaks into the instrument tent, and with a mad cackle, begins to slash the drums to ribbons. By the time the Hwarang boys find them, every single instrument is broken beyond repair.
Of course, Su-ho thinks this is Ban-ryu's doing, since he's been missing from the group for quite some time. Han-sung worries this means they can't perform, but Sun-woo eyes his former adoptive father and teacher Woo-reuk before saying that he won't let it end like this.
Ban-ryu finds his way back to the Hwarang tent, unaware that the instruments have been destroyed. Su-ho grabs him and accuses him of the deed, and says that if they all fail their test because of this, he'll kill Ban-ryu himself.
As Woo-reuk thinks about how to fix their problem, Hwa-gong reports to Princess Sookmyung about the broken instruments. She asks if this was a ploy to embarrass the royal family or if he's simply incompetent, and informs Hwa-gong that the Hwarang must perform, no matter what.
Woo-reuk works a miracle and fashions makeshift instruments out of leftover supplies. The boys go onstage and the music sounds wonderful, and their dance goes off without a hitch. The boys whirl around the platform in near-perfect synchronization, ending in a dramatic pose amid towers of flame. The crowd goes insane.
Minister Park glares at Ho Gong, who insists that the instruments were destroyed, exactly as he ordered. The officials leave the festival in an angry huff. However, the queen regent sends Hwa-gong a satisfied nod before leaving herself.
In the audience, a strange man watches Sun-woo as he celebrates with his Hwarang brothers onstage.
Hyun Chu brings the still-unconscious Ah Ro to the queen regent's tent, and the queen regent asks if she truly saw the king's face. Hyun Chu confirms it, and the queen regent draws a sword and points it at Ah Ro's throat.
Soon after, Ji-dwi sees Hyun Chu carry a large bundle to his horse and ride away with it. Pa Oh finds Ji-dwi to report that he thinks Ah Ro overheard his conversation with his mother, and Ji-dwi realizes what the bundle Hyun Chu was carrying must have been.
He rushes to intervene, sure that his mother plans to kill Ah Ro, though Pa Oh warns that he's putting himself in danger. But Ji-dwi says that if Ah Ro is killed, Pa Oh will see just how dangerous he can be.
Ah Ro is taken to the queen regent's quarters at the palace, and the queen regent asks if she saw the king. Ah Ro bravely admits that if the king is Ji-dwi, then she did. The queen regent says that she knows Ah Ro's father and that she takes after her mother, and Ah Ro replies that she also knows the queen regent resents her mother.
Queen Regent Jiso crouches down to look Ah Ro in the eye, and says that she tried to think of a way to allow her to live. "But," she says, "I couldn't find one." She orders Hyun Chu to kill Ah Ro.
Ah Ro cringes and backs away in terror as Hyun Chu raises his sword. He swings it down — but it's stopped by another sword, inches from Ah Ro. Ji-dwi stands in front of Ah Ro, looking thunderous, and orders Hyun Chu to kneel before his king.
Hyun Chu obeys, and the queen regent nervously stammers that she was only trying to protect Ji-dwi. Ji-dwi answers in a strong voice that Ah Ro is one of his subjects, the only one who can comfort the king of Silla, so he will protect her.
His mother screams his name in fury, "Sammaekjong!" But Ji-dwi yells back, "I am not Sammaekjong, I am Jinheung! This nations's king!" While the queen regent reels in shock, Ji-dwi takes Ah Ro by the arm and rushes her out of the palace.
Behind him, his mother vows to break Ji-dwi and Ah Ro apart.
Once they're safe, Ji-dwi and Ah Ro walk together, and she asks nervously if he's truly the king. He admits that he is, and asks why she's not saying anything when she keeps quiet. He says this is a huge confession for him, and Ah Ro admits that she's remembering all the times she was disrespectful to him.
Ji-dwi finds her discomfiture adorable, and laughs when she asks if he plans to kill her. He teases that since they had some good times together, he'll let her decide how he kills her.
They walk on, and Ah Ro asks if they should really be together when everyone who sees the king's face dies. Ji-dwi answers that she's his only subject who knows who he is, which makes her that much more special to him. He tells her to just behave normally towards him.
Sun-woo has been looking for Ah Ro worriedly, and comes upon Ji-dwi and Ah Ro just then. He asks Ah Ro where she's been, and when Ji-dwi starts to answer, Sun-woo snaps, "I wasn't asking you."
Ah Ro tries to act naturally with Ji-dwi as he requested, and stammers a thanks for today. She leaves, and Sun-woo follows her, though not before sending a glare in Ji-dwi's direction.
Once they're alone, Sun-woo blows up, asking if Ah Ro knows how worried he was. She angrily asks why he cares, when he's not her brother or anything at all to her. Sun-woo reminds her that he's trying to do what her real brother wanted, but she yanks her hand away and says she won't accept him.
To make his point, Sun-woo takes Ah Ro to Mak Mun's grave. He tells Mak Mun that he's sorry he took so long bringing his sister, and agrees that she's as pretty as Mak Mun said, but adds that she's not kind or smart.
As Sun-woo remembers his old friend, he tells Ah Ro that Mak Mun saw her once, wearing her wooden necklace. He says that until the very end, Mak Mun missed her and worried about her. Ah Ro kneels by Mak Mun's grave, touching the stones and crying. Behind her, Sun-woo whispers, "I'm sorry it was me, that I survived instead of your brother."
As they walk back to the city, Ah Ro asks Sun-woo what her brother was like. Sun-woo tells her that Mak Mun smiled a lot and was generous, and that he was Sun-woo's only family. Ah Ro says sadly that she would have liked to meet him in person, and Sun-woo turns her around to look at him.
Ah Ro's eyes harden, and she tells Sun-woo again that he's not her brother, even if he acts like one. Again Sun-woo says that whether or not she accepts him, he will live as her brother. He says it's the only way he can stay by her and protect her: "Protecting you is the only reason I'm still alive."
In the low-born village, Woo-reuk has a drink with the mysterious man who watched Sun-woo at the Moon Festival. Woo-reuk apologizes for not keeping his promise, but the man says kindly that this is Sun-woo's fate. To Woo-reuk's surprise, he says that Sun-woo may be able to live quietly this way, so perhaps they should leave him alone.
The mysterious man visits Ahn Ji-gong next, who is busy trying to figure out what poison the queen regent is being given. Ji-gong immediately recognizes him as HWI-KYUNG, an old acquaintance, and Hwi-kyung says he came to get his legs treated.
Ji-gong seems familiar with Hwi-kyung's weakened legs from a degenerative illness, and says that nothing can be done. Hwi-kyung sits, musing that if he hadn't lost his ability to ride a horse and go to war, he wouldn't have lost his place as successor to the throne and his sacred bone status. Well, he just became about a thousand times more interesting.
Still confused, Ji-gong asks why Hwi-kyung is here. Hwi-kyung tells him that Ah Ro was taken to the palace on the night of the Moon Festival, and that he's worried Queen Regent Jiso may be planning to harm her. Ji-gong asks why Hwi-kyung is telling him this, and Hwi-kyung says it's payback for everything Ji-gong has done for him.
The officials are in a tizzy now that their plan to humiliate the Hwarang (and by extension, the queen regent) backfired on them. Minister Park muses that Hwa-gong is more shrewd than they thought. One of the officials suggests that since the queen regent put Princess Sookmyung in Hwarang, they should put in someone of theirs.
Ho Gong visits Ban-ryu, and warns him that even if he refuses to help, things will happen as the officials want. He advises Ban-ryu to stop thinking of him as a father and find a way to ingratiate himself to Minister Park. Ban-ryu replies that he has no father at all, since one doesn't recognize him as his son yet, and the other is saying to forget about him.
The Hwarang boys get a night off, and Ji-dwi sits with Pa Oh in his private room at the Okta club. He's happy that Ah Ro is the first person to discover his identity, and levels a glare at Pa Oh when he dares to suggest she's not that pretty. He warns Ji-dwi that his mother won't let this go lightly, but Ji-dwi orders Pa Oh to kill anyone who hurts Ah Ro.
Ban-ryu is also at Okta with a couple of his lackeys, who ask if he really didn't destroy the instruments. Suddenly, Kang Sung bursts into the room and makes himself at home. He asks if Ban-ryu is thankful, since he had to do his work for him.
In another room, Su-ho tells Yeo-wool and Han-sung that he's certain Ban-ryu didn't do it. Yeo-wool quips that he can't tell if Su-ho and Ban-ryu are friends or enemies, and Han-sung breathes that it's amazing how Su-ho knows so much about Ban-ryu, but not about "the breast incident."
Yeo-wool claps a hand over Han-sung's mouth, and suddenly Soo-yeon bursts into the room, blinks at her brother, and leaves again. Okay, that wasn't weird at all. Han-sung is all That was the breast!, and Su-ho wonders why she was carrying a bottle of wine.
Su-ho's memory of the night they sneaked out comes rushing back all at once, and he recalls how it looked as though Ban-ryu grabbed Soo-yeon's breasts. He stands, calmly declaring that he's going to kill that bastard, then screams, "BAN-RYUUU!"
Ban-ryu bursts out of his private room, fed up with Kang Sung's behavior. Soo-yeon grabs him and drags him to a different room, and aww, Ban-ryu looks so flustered, it's adorable.
Soo-yeon says that the performance was great, and holds the bottle of wine out to Ban-ryu. But before he can take it, Su-ho bursts in and punches Ban-ryu, knocking him to the floor. He straddles him and settles in to deliver a solid beating.
Soo-yeon rolls her eyes and calmly knocks her brother out with the wine bottle. (That's what you get for toughening up your little sister.) She calmly rolls Su-ho off of Ban-ryu, helps Ban-ryu up, and leaves Su-ho to Yeo-wool and Han-sung.
Sun-woo visits Ji-gong, who does a quick health checkup and asks him how things are going in Hwarang. Sun-woo refuses to answer his questions, belatedly remembering to speak formally, and Ji-gong sheepishly admits that he thinks of him as the real Sun-woo. He adds that he hopes Sun-woo can think the same of Ah Ro and behave as her real brother.
Over breakfast the next morning, Ji-gong seems to sense the strain between Sun-woo and Ah Ro and tries to make small talk. He asks if they're going back to Hwarang in the afternoon, and says it's a relief to see Ah Ro's brother beside her. Sooo awkward.
Su-ho and Soo-yeon are also having breakfast with their father, who fusses at Su-ho for getting himself injured (ha, he's wearing a neck brace). Their father knows that Ban-ryu passed the essay test while Su-ho failed, and tells him that he must pass all of the physical competitions at the very least, implying that his body is his only strong suit.
After breakfast, Su-ho grabs Soo-yeon in a headlock and demands to know why she's protecting Ban-ryu. She shoves him off, hollering that she's the one who grabbed Ban-ryu's butt. She explains that she was trying to get revenge, thinking Ban-ryu was Su-ho, then was so embarrassed that she let everyone think it was Ban-ryu who did the grabbing.
The Hwarang boys reconvene that afternoon, and Hwa-gong tells them that they all passed the festival test. He says that he'll be announcing their next assignment soon, but first, he plans to give them each a disadvantage.
In a different area of the grounds, a second group of young men are gathered — the best in the country at martial arts. Dan-se is there, Han-sung's older half-brother, who wanted to join the Hwarang but didn't possess the pure blood required.
Also there is Kang Sung, looking ready to cause more trouble. Then Hwa-gong pauses to see Pa Oh, who fervently claims to be twenty-two years old, PWAHAHA.
The new group each choose a Hwarang, to act as their Nando, both servants and helpers. Ji-dwi looks annoyed to be assigned Pa Oh as his Nando, but Pa Oh whispers that this was the best way he could think of to protect him.
Yeo-wool is jealous that Dan-se is Sun-woo's Nando, and Han-sung looks deeply unhappy that his brother didn't choose him. Sun-woo asks Dan-se why he chose to be his Nando, but we don't hear Dan-se's answer.
Of course, Kang Sung chose Ban-ryu, who makes it clear that he wanted anyone but him. Kang Sung sneers that he didn't want to choose Ban-ryu either, but it was Minister Park's order.
The next competition is archery on horseback, which looks just as difficult as it sounds. The Hwarang and their Nando practice in teams, and Sun-woo wonders grumpily why he has to shoot an arrow and ride a horse. Dan-se says that's how you fight in a war.
Sun-woo asks again why Dan-se chose him instead of his brother, Han-sung. Dan-se says honestly that if he chose anyone else, he would have truly had to serve him, but that didn't seem to be the case with Sun-woo.
Sun-woo agrees with Dan-se that he has no desire to be served. He says that as he sees it, he and Dan-se are the same, and Dan-se is the same as everyone else.
Han-sung visits Ah Ro, and she guesses that he's disappointed Dan-se didn't choose to be his Nando. He asks if she's really a half-blood like his hyung, but she jokes that everyone is half-blood — half mother, half father.
Han-sung admits that their grandfather dotes on him but hates Dan-se, though he adds that he likes Dan-se more than he likes their grandfather. He says he's disappointed but glad that Dan-se chose Sun-woo, because Sun-woo is a nice person. You sweet puppy, you.
Ah Ro grows instantly flustered when she runs into Ji-dwi, clearly unsure of where to look. He asks if she's avoiding him because he's the king, and she freaks out that someone might hear him say that out loud. Then she says "king" herself, and wails that she's the crazy one.
He carries her books to the library against her objections, then asks if she's uncomfortable that he's the king. He smiles, wondering if she's worried for him, and she says that of course she's worried that the king is in Hwarang. He jokes that the situation is almost erotic, making Ah Ro start to fuss at him before remembering who he is.
Ji-dwi grows thoughtful, saying that he's never experienced the feeling of someone truly knowing him before. He looks at Ah Ro almost accusingly, and asks how she doesn't know how precious and important she is to him.
Soo-yeon visits Ah Ro at the wall later, and orders her to tell her if her brother hurts Ban-ryu. She says fiercely that she'll come over the wall and defend her man, hee.
Ah Ro reminds Soo-yeon of one of her stories, about one man who has to live as someone else, and one who has to hide his true identity. Soo-yeon asks which she likes better, but we don't hear Ah Ro's answer.
Dan-se tries to teach Sun-woo to shoot a bow and arrow from a moving horse, but Sun-woo is still a terrible rider, and just ends up shooting arrows randomly into the air. Dan-se wonders what will happen to the Nando whose Hwarang is kicked out, and jokes that he should probably change his Hwarang member.
Sun-woo bristles, declaring that he's Dog-bird, and that he will not fail. He objects to Dan-se's insults, and Dan-se quips that Sun-woo might just hit the target if he keeps practicing for another ten years.
Over lunch, Su-ho growls to Ban-ryu that he's letting this go for now, but they're not finished. In a surprising burst of niceness, Ban-ryu gives Su-ho some meat off his plate and says there's no need for an apology. Su-ho clutches his neck in annoyance, while Han-sung crows that it wasn't a breast that got grabbed, but Ban-ryu's butt.
Ah Ro enters the dining room, and Ji-dwi asks loudly if she's here to see him. Yeo-wool assumes she's really here to see Sun-woo, but he says she's not, and so she leaves, frustrated.
She confronts Sun-woo later to ask why he's avoiding her, but he sighs that he's just living as her brother. Ah Ro gets angry and says that she wishes all manner of harm would come to him before storming off.
Sun-woo spends the day practicing his horseback archery, though he doesn't seem to be improving at all. Ah Ro watches from a distance as Sun-woo barely stays on the horse, shooting arrow after arrow into the air.
After many tries, the strain gets to Sun-woo, and he experiences another blackout and falls from the horse. He tumbles to the ground and lies still, while Ah Ro rushes to his side. She feels for a pulse and can't find one, so she starts to panic.
Ah Ro beats on Sun-woo's chest, begging him to wake up. She even tries to revive him by blowing air into his lungs, but nothing works. Ah Ro cries in earnest, and says that she's actually glad he's not her brother, and that she hates herself for being so mean to him.
She keeps confessing her feelings, saying that she's falling for him, and that she's hardly able to breathe when she looks at him. She doesn't notice Sun-woo's hand twitch, which means she's completely taken by surprise when he suddenly sits up, grabs Ah Ro, and kisses her.