In Alchemy of Souls Ep 10, Jung Wook (Lee Jae Wook) completed the basic education of reading and memorising the rule books of Songrim, which was unexpected by everyone there. He told Park Jin that he had completed the task given to him and could go outside Songrim from now on, but Park Jin refused and handed another book to UK and told him that he could only go outside if he could read and memorise this book also.
Jang Wook, unaware of his tricks, accepted the task. When Jang Wook opened the book, he found nothing written there. The book was blank to the eyes of a common man and could not be read by someone who was not well trained. Jang Wook realised that this was Park Jin’s trick to keep him inside Songrim, so he decided to go outside secretly to meet Mudeok.
At the time he was leaving through a window, Heo’s granddaughter, Heo Yun-ok, saw him and he asked her to keep this secret which she kept till he returned. Jang Wook secretly went outside Songrim to meet Mudeok (Jung So Min), but he couldn’t find Mudeok at home because she was with Yulseo, who took her to the market to buy him a new umbrella as the umbrella he lent to Mudeok was broken by her. It was getting close to sunset when Mudeok didn’t get home, but as soon as she heard Jang Wook was looking for her, she rushed to meet him but couldn’t because he had already returned.
After hearing from maidservant Kim that Jang Wook had only left a while ago, Mudeok understood where he could be, so she ran and found him nearby, sailing in a valley. Jang Wook was happy to see Mudeok and told her that he thought he would not get to see her today. Jang Wook was far away from Mudeok and couldn’t hear her, so she threw a letter to him.
After returning home, Mudeok told Maidservant Kim that she applied for Songrim’s Servant Contest. Maidservant Kim told Mudeok that she didn’t need to apply for this post because she belongs to Jang’s family and she could make herself Songrim’s servant without a test. Maidservant Kim bribed Songrim’s Servant Contest holder, but this was found by Park Jin, who scolded her for doing so.
Mudeok was among the participants of the Songrim’s Servant Contest and was well aware that the content was going to be hard. Meanwhile, the crown prince, Yulseo, and Danggoo were rooting for Mudeok; they even stole Songrim’s Servant Contest paper and solved all the questions correctly for Mudeok to win the first round. Even the crown prince visited the content site to help Mudeok win the contest by giving her the correct answers to all the questions. Eventually, Mudeok became the winner of the first contest, and she also successfully won all the other contests and became the servant of Songrim.
At the time, Jang Wook was also trying to figure out how to read the Book of Hearts, which can only be read by a highly trained mind, but Master Lee helped Jang Wook by telling him that this book is a love letter and was written to the woman who was blind and no one in the Songrim who read it knew about this. He gave a hint to Jang Wook, saying, “Think of the word the love letter starts with.” Now Jang Wook understood all of this and asked some questions from Park Jin. He also asked about the name of the woman who was blind.
As soon as he started reading the book with its first word, the woman’s name, he was able to read the complete book. He eventually succeeded in this task as well and went to meet Mudeok.
At the end of Alchemy of Souls Ep 10, Jang Wook and Mudeok were sitting together under a tree talking with each other. Jang Wook told Mudeok about the love letter. When she asked what he read, he said, “I can go any distance just to see you,” and his reply to this is that he missed her too. Mudeok thought to herself that it was so foolish and pathetic of her to give him a love letter which should not be read and conveyed.