Just as Jang-Geum arrives in front of the king and the lady to decline the position of the king’s main physician, the head guard arrives with news that the prince is ill. The king and the lady queen leave the court to visit their son and find out from Doctor Jung that the prince has a strong fever, cough and perpectual fainting. Lady queen is extremely worried and asks Doctor Jung to heal her son immediately. The doctor states he needs more time to diagnose the illness. The lady queen is upset and the king calms her down.
Privately, the king suggest to lady queen that they should assign jang-geum to treat the prince. Lady queen is upset and complains to the king that he does not care about this son, only the other king-to-be son. Lady queen tells the king she told Jang-Geum to give up on king-to-be son because the king is not protecting her position and her son’s position in the palace. The lady queen complains if the king had cared about their son more she would’t have to go in such measures. The lady queen states she is merely a mother who’s trying to protect her son.
Jang-Geum runs into Min Jung Ho who asks her why she is giving up on being the king’s physician since it’s a prestigious and hard-fought reward. Jang-Geum answers she doesn’t want to cause her teacher to leave the palace. Jang-Geum packs a bag and leaves the royal court. The king sees her and flags her down to talk with her. The king tells Jang-Geum when she begged him to take her into the palace as a child, he was wondering what person would want to go to the palace, since he was resentful that he had to go. Then he got drunk over the wine she brought and next thing he knows he is the king. Jang-Geum smiles. The king smiles back and tells Jang-Geum she needs to be responsible. Jang-Geum is surprised and asks what for. The king replies she must be responsible for him being inside the palace, therefore she cannot desert him and leave by herself. The king laughs and Jang-Geum smiles at the king’s teasing.
The head guard tells the king Min Jung-Ho is the only one who supports the king’s decision to make Jang Geum his physician. The king asks the guard to bring Min Jung Ho. King remembers Min as an excellent child scholar from a long time ago. Min Jung Ho arrives. The king asks why he supports Jang-Geum becoming a physician. Min Jung-Ho replies though Jang-Geum is a woman, she is skilled and posesses strong integrity and confidence as evident through the Oh and Lady Choi scandal. The king states Min Jung Ho is right. The most important quality of a doctor is personal skills and integrity, not their gender. Min asks the king to make Jang-Geum his physician despite opposition from everyone else.
The other generals find out Min Jung Ho met with the king to give his support and become angry. The generals plan to get rid of Min Jung Ho from the court.
Jang-Geum and another nurse go outside the palace to heal the locals ill and they find that there’s a contagious fever disease going around. Jang-Geum is treating a sick boy without worrying about getting sick herself. Lady queen and the king are notified that the prince is suffering from the contagious disease. The lady queen is upset and she wants to see her son immediately but the maids stop her so she won’t get sick too. The king and the mother queen witness the lady queen yelling at the maids saying she has to see her son and the mother queen tells her to pull herself together.
The lady queen kneels before the temple and begs the gods to take her life instead of her son’s. Jang-Duk tells Kang’s wife to help her prepare the herb needed to fight the disease. Kang’s wife is teary because she is reminded that her two sons both died from the disease. The nae-ee-ohn doctors and nurses wonder where Jang-Geum is since she’s missing. The scholar brings them to town. Outside the palace, they see Kang Duk-Goo putting on a skit to teach the poors and beggars how to fight the disease. The scholar and the doctors ask the beggars why they’re cleaning. The beggars reply ‘our nurse’ instructed them to do so. The nae-ee-ohn staff ask who the nurse is. A beggar brings them to a hut where Jang-Geum is.
Shin-Bi speaks to Jang-Geum from outside the hut. Shin-Bi asks to go in and talk to her but Jang-Geum replies she can’t because she is surrounded by diseases and she’s still trying to find a cure for the disease. Shin-Bi states the prince is also suffering from the disease and asks Jang-Geum to help. Jang-Geum replies she still doesn’t have a cure and sends all them away. Lady queen begs the king to save her son. The prince passes out and things don’t look good. Lady queen continues to beg the king and the doctors to save her son. The king instructs his generals to do whatever they can to save the prince. Doctor Shin goes to visit Jang-Geum who is alone in the hut with many sick youngsters. Doctor Shin watches as Jang-Geum comforts the crying children who ask Jang-Geum if they’re dying. Jang-Geum replies no because she’s gonna heal them. Then Doctor Shin leaves quietly.
Lady queen refuses to eat. Lady Min begs her to eat but lady queen replies her body useless since she is unable to do anything about her son’s condition. Lady Min states she cannot be the first to give up. Lady queen asks if that’s something Jang-Geum said. Lady Min replies yes. The lady queen suddenly remembers Jang-Geum giving her the same advice when the king was ill.
Jang-Geum successfully finds the way to heal the children. The beggars kneel before her with tears for saving their children. Jang-Duk arrives and praises Jang-Geum and asks if she’s found the cure. Jang-Geum replies no but she found a way to fight the symptoms. The beggars are celebrating their joy. Just then soilders from the palace arrive. The beggars are scared and beg the soilders not to take their children away since they’re not sick anymore.
The lady queen appears from behind the soilders and asks if the children are really healed. The beggars reply yes, that their nurse Jang-Geum healed them. The lady queen goes to see Jang-Geum in the hut. The head guard calls Jang-Geum to come out and greet the lady queen. Jang-Geum appears and the lady queen begs Jang-Geum to heal her son. Jang-Geum returns to the palace and takes over the treatment from Doctor Jung. Shin-Bi tells the other nurses to rest since they’ve been helping Jang-Geum with the prince. The other nurses state they’re starting to like Jang-Geum and Shin-Bi. Even nurse Eun-Bi who used to detest Jang-Geum comes to help Jang-Geum. Min Jung Ho reports to the king the news about Jang-Geum saving the beggars, and the head guard arrives to tell the king the lady queen brought Jang-Geum back to the palace to treat her son.
Jang-Geum, Doctor Jung, Shin-Bi, Eun-Bi, and another medicine women work on treating the prince day and night. Finally the prince is recovering. The lady queen and the king are informed of the king’s condition. The lady queen and the king arrive to see the prince. The lady queen tells Jang-Geum she is speechless in front of Jang-Geum, for asking her to use another child’s illness as an opportunity, not knowing her own son could be in the same state. The lady queen apologizes to Jang-Geum and tells her she will from now on be her strength. The king tells his generals he wants to reward Jang-Geum by awarding her with gifts and in addition, by making her a high-ranked general. All the generals protest except for Min Jung Ho who replies he will carry out the king’s decision. The generals meet and agree that they cannot let the king go ahead with it and they complain the king again in court.
Then, the head doctor from nae-ee-ohn, Doctor Shin arrives telling the king and the court that they supports the king’s decision and all of nae-ee-ohn is behind his decision. The king asks why and Doctor Shin replies Jang-Geum treats her patients like a mother treats her child, with self-sacrifice and hope, an attitude and skill other doctors and medicine women do not have.