The attack at the banquet and the Gwiseo trick
Under the fireworks a soul shifter kills 'Bu-yeon', but she walks in alive: it was Gwiseo, Jinyowon's nail-eating white mouse.

Every Alchemy of Souls moment featuring Jin Bu-yeon, in story order. Played by Go Youn-jung.
132 moments · 5h 16m · by Favseen
Moments 61–90 of 132
Under the fireworks a soul shifter kills 'Bu-yeon', but she walks in alive: it was Gwiseo, Jinyowon's nail-eating white mouse.
The plan with Bu-yeon is revealed; Uk chases down the soul shifter and publicly declares Naksu gone for good.
At the cliff Uk relives his vows to his master Mu-deok and her confession, and admits he could not cry for her.
Uk wakes to find her beside him; she claims credit for chasing off the wraiths so he could sleep, and he lets her stay on her side of a line.
Bu-yeon haggles for a fan and watches a couple brawl over an affair; Uk tracks her down, tells her to say when she is sick, and mocks her bargain.
Uk tells Bu-yeon to look lovestruck while he flaunts her to the Queen, rejects her plea to shift her soul, and warns her never to touch his wife again.
Uk warms the cold water for the Crown Prince's turtle; hearing of it, the Crown Prince spirals into imagining what Uk meant by the gesture.
Bu-yeon thanks Uk and promises to stay by his side, but taking his hand stirs a memory and he accuses her of offering herself as a substitute.
Uk tests holding Maid Kim's hand, gets scolded for upsetting Bu-yeon, and offers a clumsy apology about chickens, pheasants and dogs.
Bu-yeon tells her mother she is regaining her powers and refuses to leave Uk; Lady Jin sees she is in love and demands Uk come apologize.
Bu-yeon rehearses a proud plea through a closed door and counts to three, only to learn she was talking to the wrong man.
Bu-yeon asks Uk to visit her mother and he declines; too late he learns Lady Jin offered to forgive them and Bu-yeon went alone.
Bu-yeon arrives alone with the gifts, then Uk appears behind her and formally apologizes to Lady Jin.
Uk talks Lady Jin into giving them a room; alone, Bu-yeon misreads his intentions before he asks her to open Jinyowon for him.
Sneaking through the garden, Bu-yeon tells Uk how she imagined sitting alone atop a tall tree hoping to be rescued, leaving him shaken.
Uk accuses her of confusing him; she knows of a tall tree he once promised to climb, and insists that it is her hand he is holding.
Bu-yeon senses Yul's energy at Jinyowon; meanwhile a captive So-i names one suspect after another rather than give up her secret.
Uk asks Lady Jin to let him into Jinyowon as Yul and Bu-yeon find the wounded So-i, who tells Bu-yeon she only thinks she is Jin Bu-yeon.
Yul understands Bu-yeon was Naksu all along; overwhelmed, he asks her to let him stay a moment and begs her not to tell Uk.
Bu-yeon insists she came for her friend Seo Yul, not Uk's, and refuses to go home until Uk gives in and walks her back.
Bu-yeon recalls meeting So-i and Yul, says Yul would have been a kind husband, then teases Uk to summon fireflies or fireworks.
Bu-yeon locates the hidden earthenware and explains she sees others' memories by touching their things, then is told she resembles spring.
On the boat Bu-yeon suddenly hangs over the edge, recalling having no strength, and realizes this memory is hers.
Feeding the turtle, Bu-yeon and the Crown Prince, whom she takes for a eunuch, swap marriage advice and confessions of feeling like a fraud.
Showing off her Songrim plaque, Bu-yeon speaks of a harsh master in words that shake Uk, then vows to grow strong and protect him.
Bu-yeon wants to see whether the giant tree she remembers is real, and Yul offers to take her to Danhyanggok.
Uk hunts for the jade, learns she is going to Danhyanggok with Yul, and the two squabble over friendship before he leaves rattled.
At the place where they first met, Yul recalls how much he liked her as a child and his regret at doing nothing.
Cheonbugwan mages beat So-i over the missing parasite while her servant finds Yul on his trip with Bu-yeon and tells him she was taken.
Breaking her promise, Bu-yeon tells Uk that Yul is severely ill and she saw a strange energy inside him.