The investigation really gets underway as another scholar is taken away by the assassin in the mask. Chae Yoon tries to hide his special skills that he learnt while he was in the north, but he can’t hide his passionate personality and this is what gives him away in the end -Finally his true identity is discovered. We see more of the king and his quirky research and some cool ‘flying’ skills from Chae Yoon and the mysterious assassin as the mystery develops.
The king gives Chae Yoon’s investigation notes back to Mu Hyul. Mu Hyul goes and tells Chae Yoon to do everything he can to solve the case, but he’s irritated by Chae Yoon’s behaviour and attitude. He doesn’t realise this is all an act. Mu Hyul will tell the captain of the kyomsa department about Chae Yoon’s position as head of the investigation. But as Chae Yoon turns to get dressed, Mu Hyul notices the scar on his arm. The shape of the cut means it was made by Mu Hyul’s own sword. So he realises that he must have saved Chae Yoon in the past but he doesn’t remember him. He’s about to say something to Chae Yoon but thinks better of it.
Chae Yoon bumps into Cho Tak, a soldier he knew from the north. He has been sent to the kyomsa department too. Another guard, Park Po, comes along and insults him for coming from the north and the two men start to fight. Chae Yoon breaks them up.
Chae Yoon and Cho Tak are patrolling when they see the scholar Yun Pil trying to get into the Institute. Chae Yoon tells him that he can’t go in on the king’s orders and watches him suspiciously as he walks away.
At the kyomsabu, the guards assemble. The captain tells the three guards to work together on the case. Then they all set off to see the coroner. The light-hearted comedy music doesn’t suggest they will solve the case though!
Mu Hyul and Jeong In Ji are looking for the king. Prince Gwangpyeong (King Sejong’s 5th son, addressed as tegun ma-ma) tells them he’s at the Sangrimwon. The Sangrimwon is the place where the palace plants, flowers, and crops are grown. When they arrive, Jeong In Ji covers his nose from the smell of fertiliser. They ask one of the nobi where the king is but the nobi doesn’t answer. At first they are annoyed but when the nobi turns around they see that he IS the king! (Nobi always wear white) He’s fertilising the plants himself. The king seems to be doing all kinds of research including research on fertiliser and he’s frustrated about how slow the progress is.
He takes them over to a nobi who is on the ground barking with a dog. He’s practising 구희 gu-hui – when people try to copy the sound of animals or musical instruments with their voices. (This must be related to the king’s research for the creation of hangul?) The king is trying to find out what sound the dog makes. Is it ‘wol wol‘ or ‘ak ak’ or whatever? He makes Mu Hyul and Jeon In Ji and the court ladies have a go at barking too – which they do rather self consciously! One of the ladies thinks the dog sounds like ‘wang wang’ The king pretends to get annoyed with her and she begs for mercy worried that she’s angered him but he’s only joking. ‘Wang Wang’ is actually the Korean animal sound for a dog but ‘Wang’ also means King – so the king pretends to be offended.
Chae Yoon and the guards go to see the coroner (who’s also the butcher). But on his way he bumps into To Dam Baek, the head nobi. He tries to hide his face in case she recognises him. She glances at him but then moves on. (The guards have to go to Banchon where the nobi live to see the coroner – the coroner’s job was a low class job because it meant dealing with dead bodies. So the coroner will always come from the lowest class – chonin. In the MBC drama Dong Yi, her father was also a coroner.)
The king wants everyone to think that Chae Yoon is in charge of the investigation but really plans to have someone else in charge. Then they can see what happens. He doesn’t seem to think that Chae Yoon has the ability to solve the crime. He wants to know what happened to the scholar and tells Mu Hyul to bring the coroner to him.
When they arrive at the coroner’s, Chae Yoon almost come to blows with a very creepy looking helper. Then they all look at the dead body to ascertain the cause of death. The coroner explains that the blue marks on the body suggest suffocation but there are no marks around the neck or signs of a struggle. Chae Yoon’s expression suggests he has an idea how this happened.
Chae Yoon has recognised that this is an assassination method of suffocation using water – a master’s skill. He thinks back to his time in the north in the army when he came face to face with Master Lee Bang Ji. He remembers his special skills including chul sang sul where he virtually flies through the air knocking out lots of soldiers single-handedly. Chae Yoon was impressed and begged him to teach him. But he refused. At first.
Meanwhile Mu Hyul is practising his art too – the scar on Chae Yoon’s arm has bothered him. And he also remembers Master Lee Bang Ji – the only man he has ever lost a fight to. And that time Lee Bang Ji refused to kill him.
In the 사옹원Sayongwon (the place that supplies the king and the palace with food) the court ladies are checking the meat for the king. The coroner/butcher has been called for the meat but he doesn’t know that he is really there to see the king. The king wants to confirm that the scholar’s death was murder and asks the coroner about the cause. The coroner has kept the information secret as instructed and tells the king about the assassination method known as koniksu-sagon. He explains that a man can be drowned with drops of water – a technique used in the north and China. The king tells him to bring updates directly to him and Mu Hyul.
On his way out, the coroner is stopped by Jo Mal Seng who wants to know what he’s doing in the palace. The coroner is sworn to secrecy so merely says he came to bring the king’s meat and leaves it at that.
Now we go back in time to when Master Lee Bang Ji showed Chae Yoon the assassination method – he practices blowing a drop of water through a pipe through a target. We see that the assassin in the mask uses a calligraphy brush to blow a drop of water into the scholar’s nostril – this technique stops him breathing.
Jeong In Ji wonders of the scholars should be told about what they are really doing in the Institute of Learning but the king insists that the real reason be kept secret. Meanwhile, Lee Shin Chok tells the captain of the kyomsa to report all the updates of the investigation to him. Hmm. Suspicious.
At the temple the young scholars bicker with each other. The young scholars have heard rumours about the murder. They are told to go back to the Institute of Learning the next day, but then they notice that Yun Pil is not there.
The head nobi is with a mystery man and reading the name written on a piece of paper – Yun Pil, a scholar at the Institute. She burns the paper to destroy the evidence. Yun Pil will be disposed of this evening.
Jeong In Ji arrives to see the king but is surprised to hear a woman’s groans coming from inside! It’s the King and his son inside. The scholar tells the King that Yun Pil has disappeared.
Yun Pil has sneaked into the Institute of Learning and is checking around the crime scene – the desk of the dead scholar. He finds what he’s looking for hidden under the table. Meanwhile, Chae Yoon and Cho Tak arrive at the institute. When they go in, Chae Yoon realises that someone else is there. Yun Pil hides under the desk but then makes a sound and rushes through the paper screen doors to get away. Chae Yoon runs after him. A cool move – as Yun Pil throws some evidence on a fire, Chae Yoon flies through the air to grab the paper before it burns. Meanwhile, Cho Tak kicks a small metal ball that man getting away on the back and knocks him out.
They are surprised to see that it’s Yun Pil. They hear the sound of an owl and from the sky some little daggers fly down along with the assassin in the mask. He comes down and grabs Yun Pil and flies back up into the trees with him. They realise that this is chul sang sul – the technique of ‘flying’. Other guards are coming so Chae Yoon hides the paper he saved from the fire.
The king is informed that Yun Pil was taken away. Then he turns to ask a court lady behind the screen what she thinks – So Yi can’t speak so she writes it down on paper. Then the king agrees with her and burns what she wrote.
Chae Yoon and Cho Tak wonder who can do chul sang sul – leap very high like flying. Chae Yun reads the paper that Yun Pil tried to throw away – gun-na-mi-yuk. They try to work out the movements of the assassin – working out how far he can jump etc. They check the footprints and the roof tiles and decide that he must still be in the palace.
So Yi has the king’s seal which lets her go past the guard and into the chuchaso – the place where the characters are made for printing books. She goes in and starts looking for something through the metal characters. Someone from behind demands to know who’s there.
Chae Yoon and Cho Tak go to the chuchaso telling the other guards they came because they saw something suspicious. They smell burning and Chae Yoon rushes over. He is convinced that the assassin is inside the building so pours a bucket of water over his head and puts a straw mat over himself and goes into the building. He pulls out a court lady, So Yi, then grabs her by the collar and demands to know who the assassin is. He is passionate and angry. Just then Mu Hyul arrives and as he watches him he remembers a young boy shouting at one of the guards just like this. Finally, Mu Hyul realises who Chae Yoon is…