Park Jin shows Yul the blue mark on Naksu's body
At Songrim, the leader teaches Yul how a soul leaving its body leaves a blue bruise, and they find a bird whistle on the dead assassin.

Every Alchemy of Souls moment featuring Park Jin, in story order. Played by Yu Jun-sang.
114 moments · 4h 21m
At Songrim, the leader teaches Yul how a soul leaving its body leaves a blue bruise, and they find a bird whistle on the dead assassin.
Dang-gu rushes to his uncle with rumors about Naksu, gets scolded for hanging around bars, and reveals Uk has been sent to train with a monk.
Unable to draw his father's sword because of the spell on him, Uk is told no one will open his gate of energy, and vows to find a master himself.
Masked intruders break into Songrim, the Training Center burns, Jeongjingak is emptied, and Mu-deok realizes her old master sent them.
Naksu's body is gone and a spy is suspected; Uk teases Mu-deok while the others discuss how soul shifters pick similar bodies.
Everyone in Songrim is gathered and locked in while Jin Cho-yeon brings Gwigu, the Jin family's ghost dog that sniffs out sorcery.
The Four Seasons are together again for the first time since Uk and Cho-yeon called off their wedding, and it shows.
Mu-deok learns he broke the pottery to save her; the Songrim leader confronts Uk and forbids him from moving or speaking.
The king considers promoting Jin Mu for killing Naksu's men; Songrim objects, and Jin Mu asks to burn Naksu's body and keep her sword.
Pressed about the infant, Jang Gang says sealing his power is the only way the boy lives, and calls him the son of a dead man.
Uk tells the Songrim leader he poisoned himself and his maid only obeyed, then refuses treatment unless Mu-deok is treated too.
Heo Yeom admits he opened Uk's gate and gave him extra energy to recover; Park Jin insists he take it back to keep Uk far behind.
Heo Yeom demands the wine hidden in Park Jin's room, teases him about never getting over Do-hwa, and finds the bottle already empty.
Over stolen wine, Dang-gu and Yul find Mu-deok suspicious for faking blindness, then Yul abandons Dang-gu as his uncle arrives.
Maidservant Kim raises the rumor that Park Jin is Uk's father; he brings up her acorn jelly for Jang Gang, and both admit to old, unhealed loves.
Park Jin remembers being told Uk's father was the late king, and that a destined king would be seen as treason, so Uk must seem ordinary.
Uk asks to join Songrim and offers Naksu's sword; instead he is banished and, for losing the Spirit Plaque, sentenced to a hundred lashes.
After 99 lashes Uk refuses to leave, demands the leader deliver the last one himself, then has Mu-deok take the sword.
A plea to let Uk return is shut down; over a soul shifter's petrified victim, the Songrim leader explains the alchemy of souls needs Hwansu mastery.
Uk shows the Songrim leader he can now draw his father's sword and begs to be taken in, but unbound, his arm cannot hold the blade.
Cho-yeon brags that Uk beat the Crown Prince, but the leader hears Uk threatened the Prince and orders him locked up as dangerous.
Uk vows to become Gwanju like his father; Park Jin tells him he is not Jang Gang's son and should stop dreaming.
Nursing a wound he chose not to dodge, Park Jin muses about claiming to be his father; Maid Kim's jab about his looks turns into a grudging truce.
Royal guards come for Uk after the duel challenge; warned he could lose his arm or life, he slips away to Sari Village with Mu-deok.
At a Unanimous Assembly, mages who once taught Uk propose stripping his powers; Songrim accepts the royal duel instead.
The soul shifter was a Cheonbugwan star recorder, so Jeongjingak mages search the office and ask to see its secret room.
Cho-yeon's mother offers to block the King's order with the Jin family plaque, if Uk marries Cho-yeon; Cho-yeon says she still wants him.
Debating the Jin marriage, an elder admits he once left his master for love; then an intruder breaks the barrier and Heo Yeom greets his master.
Master Lee suspects Cheonbugwan, reins in Heo Yeom, teases grown-up Park Jin, and reveals he took the dog Gwigu to hunt soul shifters.
Yul tells the Songrim leader of a girl hiding in Danhyanggok whose father wrote down the stars, and learns of a recorder killed by the four families.
At Songrim, the talk turns to Gwigu's origins and to the only way souls can be shifted without Hwansu: the ice stone is back in the world.
Maid Kim asks if he would lock her in like Jinyowon's leader; he will not lie to her, and only admits too late how it would break his heart.
At Cheonbugwan, Songrim's leader hears that Naksu's father was a soul shifter and is shown the hidden star plate from the night Jang Uk was born.
Park Jin asks about Jang Gang's secret spell training before Uk's birth, and the talk turns to a shocking claim about whose son Uk is.
Songrim mages spin the Tansu killing into a legend of an invincible Naksu in blue cloth who is coming for them next.
Shaken by fears for Uk, Maid Kim plays at being someone else; Park Jin offers his back, admits he never wants to hurt her, and asks her to keep it up.
Asked to keep Uk away from the formal duel, Songrim's leader says he will only watch, whether Uk runs or dies.
Uk receives the uniform, Spirit Plaque and Book of Regulations, bows to the leader and his peers, and the mages head off to party on the Jang family's tab.
Two old friends reminisce about Uk as a newborn, then squabble over a raisin tree pill and whether one of them is going gray.
Uk and Mu-deok split Master Heo's pill, and Park Jin keeps trying to hand his to Maid Kim as she walks away.
Drunk Master Heo reveals he brought Do-hwa to Sejukwon to match her with Park Jin, who never said the words; his shrug at lost love sends Maid Kim off.
Hungover Uk asks for Mu-deok and gets the maid from the inn, learns who Yun-ok is, and Maid Kim says she reminds her of Madam Do-hwa.
Park Jin's logic sets off a spat with Maid Kim that everyone can read, and Dang-gu gets scolded for trying to follow Uk and Yun-ok.
The leader refuses an exception and probes whether Uk needs his maid to reach a secret master; to protect her, Uk gives in.
Uk recites Songrim's rules from memory to win his freedom, but the leader says he only memorized them and sets a new condition.
The leader reveals he is keeping Uk close only to stop trouble, expecting Jang Gang to come once he hears his son entered Songrim.
Park Jin scolds Maid Kim for gifting a scarf to get Mu-deok into Songrim; wounded pride turns it into a falling-out neither wanted.
Told Uk read the book and carried his collapsed maid to Sejukwon, Park Jin realizes Mu-deok has always been at Uk's side.
Master Lee visits Maid Kim with flowers; Park Jin shows up worried and empty-handed, and she tells him she wants flowers, not weeds.
Park Jin scolds his nephew for courting Jinyowon's heir; Dang-gu wishes for a sibling to inherit instead and gets chased out.
Park Jin wants Master Kang's body examined for sorcery before cremation; Jin Mu objects and Lady Jin sides with him.
Two masters piece together that Naksu, Cho Chung's daughter, unknowingly disposed of Jin Mu's discarded soul-shifter bodies.
At the cremation Park Jin has Yul pour energy into the body; it turns out to be a soul shifter, and Songrim claims the case.
Park Jin confronts Jin Mu over the cover-up, then the rampaging soul shifter fights until Cheonbugwan strikes it down.
Jin Mu reminisces with Maid Kim about serving Jang Gang and asks to share biscuits with Uk; Park Jin refuses and sends him away.
Park Jin sends every trained mage to Sejukwon except Uk, telling him he is excluded and may go home.
Park Jin offers a flimsy reason for Uk's visit, Uk accuses Jin Mu of hiding a soul shifter, and the Crown Prince orders a check on the eunuch.
Park Jin apologizes and offers to fix the basin; when Jin Mu insists on punishing Uk himself, Mu-deok's wailing plea gets him released to Songrim.
Mu-deok explains why she made a scene; Park Jin says he knows they told the truth and suspects Jin Mu holds the ice stone.
Songrim's leader asks for Jinyowon's relics to unmask soul shifters; Lady Jin refuses and he accuses her of a deal with Jin Mu.
Master Lee explains that some are born able to grasp energy and others fear them, as Uk catches the Golden Fish and Mu-deok tells him he has reached Chisu.
Asked why Master Lee helps him, Uk 'reveals' the family matter: Lee is winning over Maid Kim, and Uk offers Park Jin the first chance.
Master Lee says his chastity is over, Park Jin insists she still loves Jang Gang, and he is told he is the slow-witted one.
Mu-deok eyes the bow Park Jin once used on her and teases him about forgetfulness; impressed, he orders a quiet check into her past.
Park Jin says the broker exposed her eyes; the broker claims she faked blindness to escape debt, and Mu-deok plays along.
Alone with Mu-deok, the broker admits Ju-wol paid him with Uk's money, warns her about So-i, and says he likes her anyway.
Park Jin accuses Mu-deok of killing the broker; she denies it, the dead thugs point to a swindler from Sari Village, and she slips away.
Park Jin explains the bodies at the ferry inn to Maid Kim and warns that Mu-deok fled instead of proving her innocence.
Cho-yeon tells Park Jin she saw Mu-deok at the inn, insisting it was her first visit, and suspicion shifts to the swindler So-i.
Park Jin tells each that the other confessed their secret; they must guess what the other said, or one of them dies.
Both told Park Jin they love each other; Uk teases Mu-deok, she orders him to choose life over love, and he refuses.
Jinyowon's leader demands Gwigu back, accuses Master Lee of stealing it, and kills the dog that housed the relic to protect her daughter.
Ho-gyeong rejects a match and eyes the Crown Prince for Cho-yeon; Cho-yeon refuses, Dang-gu declares himself, and both get thrown out.
Songrim's elders fear Jin Mu will use Uk's birth against them, and pin their hopes on the wandering Jang Gang hearing the soul shifter rumours.
Park Jin fishes for whether an older, plainer man has a chance; Kim thinks he means himself, while he thinks she means Master Lee.
Dang-gu pleads for his love; Park Jin sends him to Uk's house to watch for one man: Jang Gang, Uk's father.
Jinyowon's leader lists Songrim's overreach, presents her daughter, and announces the ice stone has been in Jinyowon all along.
The assembly calls Songrim's crusade a fraud, Jinyowon refuses to destroy the stone, and the families shout Songrim out of the debate.
Ho-gyeong claims the right to convene the assembly for Jinyowon; Songrim's leader orders his mages to stop anyone taking the stone.
Outside, the elders find an invisible barrier around Jeongjingak with the Crown Prince and their children trapped, and start blaming each other.
Before the King, Songrim reveals the scroll is a confession to Jin Seol-ran: Seo Gyeong spared the ice stone for his dying lover, and she refused it.
Pressed by Songrim, Jin Ho-gyeong recalls her stillborn baby and admits she opened Jinyowon to Jang Gang, losing the ice stone.
Dang-gu reports the real Queen is found and urges discretion, then names Uk's father, Jang Gang, as the Songrim mage behind everything.
A disfigured woman locked up for years is brought before the King and declares she is Queen Seo Ha-seon, robbed of her body by a shaman.
With no mark to prove it, Songrim produces ashes said to hold Gwigu's power; the false Queen panics, and the bluff proves she is a soul shifter.
Cornered, the shaman says no one may call her evil: Jin Ho-gyeong let the ice stone out, Park Jin hid the truth, and Jin Mu stood by.
Trapped in a scarred body, the Queen asks why Uk is spared; Songrim answers he lost his powers and his right to lead Cheonbugwan.
A message from Jang Gang tells Maidservant Kim and Park Jin that Uk was conceived when the late king shifted souls; they vow to keep it secret.
Touring houses, Maid Kim describes her dream home; when Park Jin offers to gift it for her wedding to Master Lee, she tells him he is the one.
Hurt that Park Jin never noticed, Maid Kim shouts about the balsam-dyed fingernails she imagined, then storms off demanding a 100-room house.
Uk tells Park Jin he may take Maid Kim away for good; Park Jin finally stops her with balsam seeds and asks her to wait for them to bloom.
Uk wants answers about his father; the elders learn Jin Mu framed Lord Cho Chung, and fear Jin Mu could expose Uk's secret.
Park Jin and Jin Ho-gyeong argue over whose family Dang-gu is marrying into while Uk wonders where Mu-deok is.
Barred from mourning properly, Maid Kim pleads to stop a body being burned like a criminal's, and Park Jin says Songrim has no say.
Retired Park Jin makes crocks of kimchi nobody wants; Maid Kim tries to slow him down, then cries thanking him for stepping down.
Park Jin cooks for Seo Yul's return; the friends gang up on the next 'victim' and Yul politely gives up on the charbroiled deodeok.
Hearing of Bu-yeon's lost powers, Jang Uk asks whether a priestess could extract the ice stone, even if it kills him, to finally find peace.
Park Jin sets out to prove a proverb wrong, he and Maid Kim volley 'red beans' versus 'soybeans', and news of Jang Uk's bride shocks him.
Over failed red bean porridge, Park Jin warns Jang Uk not to marry someone who would take his life, and Uk explains how a red bean lie survives.
Dang-gu's uncle serves a honey-or-fish-sauce rice cake game with a lesson on destiny, before news breaks of Naksu's rumored return.
Teasing about Master Lee's old feelings for Maid Kim makes Park Jin brood, and he punishes the gossips with a pot of spicy beef soup.
Told Maid Kim might tend to Master Lee, Park Jin suddenly develops stomach knots and a fever so she stays by his side.
Park Jin and Maid Kim hide from late visitors, laugh about feeling young, and he proposes to Kim Yeon of Wol Fortress as the household cheers.
Bu-yeon locates the hidden earthenware and explains she sees others' memories by touching their things, then is told she resembles spring.
Park Jin sulks that Uk always comes first and poses the drowning question; Maid Kim turns it back on him, and both admit how much they care.
Facing Uk's sword, Go Won admits Uk's rage is aimed at him and asks him not to waste years of restraint; Songrim declares it stands with Uk.
Park Jin teases Uk with a drowning riddle about himself and Maid Kim, then tells him not to abandon Bu-yeon to save Yul.
Park Jin admits he told Yul to stay out of it; Maid Kim calls him out, and Uk vows to win over Lady Jin.
Uk tells his elder he is going north and asks if he will back him; he says he knows his target and what he must protect.
Maid Kim wants to follow Uk north, Park Jin protests, and Uk tells her to stay with his uncle.
Park Jin offers to move north after the wedding and notices her ring on the wrong finger; she keeps it anyway as a promise.
As relics escape a collapsing Jinyowon, Maid Kim, trapped inside, begs Park Jin to seal the door, calling it what must be done.
Jin Mu and the King offer Park Jin the power to save Maid Kim; he admits he wants it, then vows to stop them anyway.
Maid Kim dotes on Dang-gu's twin boys while Park Jin grumbles about newlywed trips, until a sudden queasiness hints at news.