The crown prince vows to crush Jang Uk
Jin Mu praises the prince's swordwork, mentions Uk's open gate and the sword he took, and the prince takes the slight personally.

Every Alchemy of Souls moment featuring Crown Prince Go Won, in story order. Played by Shin Seung-ho.
99 moments · 4h 06m · by Favseen
Moments 1–30 of 99
Jin Mu praises the prince's swordwork, mentions Uk's open gate and the sword he took, and the prince takes the slight personally.
The Crown Prince arrives for Naksu's sword and also demands the late Gwanju's sword; Uk refuses and the Prince proposes a fight for it.
The Prince dares Uk to push him over a line; Uk takes a beating until Mu-deok's chamber-pot splash forces the Prince across it.
Uk unsheathes his father's sword but cannot control his arm; a binding bracelet stops him, and the Prince dares the four heirs to fight him together.
Mu-deok offers to drink chamber-pot water as an apology, Uk insists he should, and the friends join in until the Crown Prince gives up.
Mu-deok hands the Prince Naksu's sword with lavish flattery so he can call himself the winner; he gives her a new nickname.
Master Heo's plea backfires: Jin Mu wants Uk's sword arm cut off, then proposes an official duel with the Crown Prince.
At a Unanimous Assembly, mages who once taught Uk propose stripping his powers; Songrim accepts the royal duel instead.
Mu-deok begs the Crown Prince for rescue by insulting Uk, receives his cinnamon sachet, and gamely drinks cinnamon wine she clearly hates.
Over the King's hunt for the King's Star, the Crown Prince is told to kill the son of the Gwanju who made the divination.
Snatched from Chwiseonru despite the sachet, Mu-deok is dressed as a gisaeng and brought to the Crown Prince, who says the look does not suit her.
The Prince asks Mu-deok to keep Uk away from the duel, then offers her a place; she refuses to serve just anyone, leaving him baffled.
Brooding over Mu-deok's refusal, the Crown Prince finds her in his chambers, but she smells wrong; he unmasks the visitor as something wicked.
The Crown Prince is told the maid broke the yin-and-yang jade meant for the wedding rings and fled, then Yul turns up looking for her too.
Warned the vault's relics can trap anyone forever, Yul and the Crown Prince insist on going in with Uk, and are given one hour.
The Crown Prince teases Uk about inheriting Jinyowon's treasures, a noise startles them, and calm Yul marches off the wrong way.
Comparing notes on the illusion, the Crown Prince learns the sachet he gave Mu-deok has been put to use keeping flies off the outhouse.
The broken mirrors lead them to the Mirror of Longing. Its leader refuses even a royal order to move it and vows to seal the door on Uk.
As the door is about to be sealed, Yul is sent to drag Uk out while Uk tells the mirror his plan to keep her by his side, and that he misses her.
Uk ties a cloth over Mu-deok's dazzled eyes, then Dang-gu, Yul and the Crown Prince each arrive offering to take her for treatment.
The Crown Prince learns Mu-deok sold his gift, claims sole rights to her nickname, and sees the capital wearing Naksu's blue cloth.
With the king watching and Uk's Cheonbugwan inheritance at stake, noon arrives and the doors close, until Jang Uk is announced.
Cho-yeon begs her mother to stop it, Uk defends as coached, an order goes out to smash the water crocks, and Uk ends the match with Tansu.
To everyone's alarm, the defeated Crown Prince arrives with wine, pours Uk a gracious congratulatory drink, and gets one back.
Outside, the Crown Prince confesses how much he hates her master, threatens to kill her first next time, then checks where his sachet really went.
Go Won finds Uk outside Songrim; Uk bribes his silence with a honey biscuit, and the prince warns him about mages nearby.
While the prince eats, schemers note his softening toward Songrim and say Uk's constellation plate will force him to kill Uk.
Go Won and Yul get the test papers and solve them, working out a tricky seating puzzle and how to wash ink from clothes.
The prince drops in to encourage the applicants, and Mu-deok's name is read among those who passed the written test.
The prince claims credit for her answer sheet and belittles Uk; Mu-deok steers him into a wager and stakes her most precious possession.