Uk lures the soul shifter to the secret room alone
Uk takes Master Kang on himself to save the others; Mu-deok decides to rescue them one last time and runs for the secret room past Yul.

Every Alchemy of Souls moment featuring Mu-deok, in story order. Played by Jung So-min.
233 moments · 9h 09m · by Favseen
Moments 211–233 of 233
Uk takes Master Kang on himself to save the others; Mu-deok decides to rescue them one last time and runs for the secret room past Yul.
Sword drawn and power regained, Mu-deok faces Uk, who reminds her of their promise and lets her decide; she asks for his other promise.
Trapped in the barrier, Mu-deok confronts Uk about the overflowing power he cannot control and holds him to his promise.
Inside the barrier Uk proposes using Tansu to turn the ice stone's fog into rain at the cost of all his power; Mu-deok forbids it as his master.
With no way to transfuse blood, Mu-deok uses the worm carrying Jin family blood on the badly wounded Yul and begs him to live.
Uk will use Tansu even if it costs his powers or life, asks the Crown Prince to handle the aftermath, and Mu-deok gives her blessing.
The King's Star appears, the barrier falls and the crowd hails the Crown Prince, while Uk and Mu-deok, both powerless, are just glad to be together.
Mu-deok tells Yul he is a terrible liar, thanks him for quietly protecting her, and gives back the token from Danhyanggok.
Yul checks her pulse as an excuse to share three breaths, and the two quietly part, remembering their time at Danhyanggok.
Mu-deok is dressed as a stand-in bride for a fitting and the women cannot stop admiring her.
Uk finds Mu-deok in the bridal room, says even 13 proposals get easier, ends his training as her pupil and asks her to marry him.
A gossip promises to spread news of the marriage, and Mu-deok's defense of Uk turns into an embarrassing rumor about their nights together.
Ordering matching rings, Mu-deok learns of Uk's past ring-holding young ladies, hunts for more, and settles for his hand as her ring.
Yul still hurts after healing; Mu-deok learns So-i gave him her blood and that a parasite is in his body, and plans medicine.
Maid Kim tells Mu-deok to stop doing chores as Uk's future wife, and Mu-deok's assumption about Maid Kim and Park Jin leaves both exasperated.
Shopping with Uk, Mu-deok goes deaf to his calls after hearing bells, while Jin Mu watches and finds new hope in Naksu.
The Crown Prince admits he knows Uk saved everyone, confesses his bitterness and jealousy, and tells Mu-deok to leave with Uk far away.
Tipsy at her farewell drink, Mu-deok fails to fly to the roof, nearly brags she is Naksu, and tells Uk she likes him before falling asleep.
Calling her Naksu, Jin Mu pours his power into Mu-deok to bring hers out, knowing she will run wild.
Under Jin Mu's control, Mu-deok attacks Cho-yeon's father at Sejukwon; Dang-gu fails to stop her and Cho-yeon weeps over her father.
Coming to herself, Mu-deok finds Uk wounded by her hand, as memories of their ring and their sword promise flood back.
Mu-deok wakes freed of the bells as Jin Mu predicts her end, while a voice tells Uk, the King's Star, that this is not his end.
At the cliff Uk relives his vows to his master Mu-deok and her confession, and admits he could not cry for her.