Amidst the dead silence of the forests and the mountains of Bukhansan, suddenly, the crushing sound of large stones hitting the ground tears apart that silence. After that, another series of stones as big as five adult humans follow the first stones to fall down hills and crush the simple houses within the commune of Bukhansan. Among the crushing of the stones, a young boy's screams can be heard as he dashes out of a house that has been demolished by the weight of more than three stones.

"Ahjuma? Ahjuma? Where are you?" After dashing out of the house, the boy keeps hovering around as if looking for someone among the mess left behind by the demolition of the stones. "Ahjuma? Answer me!" He keeps calling, but from the mess that was previously his house, no response is given, and no sign is shown that there is a living being inside the collapsed house, only the cows and cattle in the animal house screaming in a panic, banging on the walls trying to get out. His mind is suddenly taken back to the peaceful days when he used to tend to the cows and the cattle with his aunt. Although he would always get nagged at by his aunt for not collecting the chicken eggs when it was time, for not washing the animals thoroughly, or for not shutting the doors carefully, he would give everything to hear her voice again. And suddenly, the boy feels a panic spread throughout his body, as he knows deep in his bones, he would never get to see the woman again, and those days would now only be a memory in the back of his mind.

Down the road to the collapsed house, a man and a woman ran out of their own house to the road just before the house went up in flames right before their eyes. "Fire! Fire!", they scream as they look back to the sea of fire that they had just escaped from. Just as they are about to catch their breath, ten arrows suddenly fall from the sky towards where they are standing. The man and the woman immediately avoid the arrows, but one arrow still manages to hit the man's shoulder. He yells out in pain, and the woman quickly runs to his aid, helping him step by step to a nearby shelter. But this soon proves to be in vain, as the arrows seem to follow them anywhere. Just as they are about to step into a nearby house, another series of arrows come down from the sky, each one bringing with it an angry flame. The arrows quickly light the house on fire, and in only a few moments, the wooden house collapses on the ground like a pretend house made from a bunch of sticks by children. 

The couple once again dashes out of the house. On their faces, sweat begins to drip uncontrollably. Neither of them had expected anything like this would happen. It was only a nice and peaceful night like every night they have stayed here for the last ten years. But in a blink of an eye, they had lost everything they ever owned in a ruthless fire, and now they may even lose their lives to the endless arrows that keep attacking them. The couple looks around themselves, and finds that surrounding them are their own neighbors and friends from the same commune, all with the same terrified expressions on their faces. Down the main road, houses are either crushed by stones from the mountains or burnt to the ground by the ruthless fire from the arrows. The sounds of people screaming in pain and calling for help are deafening, and, for a moment, the woman stops in her steps and contemplates their doom right here in the remote mountains of Bukhansan. Tears suddenly stream down her face uncontrollably. Fear has paralyzed her, as her body fails to comply with her instinct, which is screaming for her to run. At the same time, more arrows and stones come falling from the sky like the rain on the most stormy day. As the couple is focused on the scene before their eyes, they do not notice the arrows coming their way. Two arrows are about to hit the man and woman from behind when a dark and tall figure quickly comes to the rescue and stops the arrows with his bare hands.

"Master!"

"Master!"

As the couple turns around to see the commotion behind them, they recognize the familiar and solemn figure in front of them, which is no other than the Master of the Children of the Mountains in Bukhansan. Kyuhyun gives them a quick head-to-toe scan, and when he sees no injuries on them, his brows seem to slightly relax.

"Are you injured?" He makes sure to check on the couple again for injuries, and when he receives a shake of the head from both of them, he turns to the man standing right behind him: "Take them and the rest of the members to the Temple at the foot of the mountains. Tell them what happened here, they will let us stay there for a few days while I rescue the rest of the members here."

The man immediately nods his head. On his face, sweat and dirt cover his forehead and cheeks. He quickly raises a hand to wipe it all away, but only seems to smear it more onto his face. He takes another look at his leader, who rushes into the fire without a second of hesitation. Taking a deep breath, he turns to the couple standing in front of him, and signals for them to come with him. It is gonna be a long night.

Meanwhile, amidst the fire and smoke which seem to have swallowed the commune whole. Kyuhyun rushes through the main roads, carefully examining each remains of the collapsed houses for anyone who is injured. The roads seem to have gotten much quieter, as most of the residents have followed his instructions and gone to the Temple at the foot of the mountain for shelter.

Kyuhyun looks in the direction of the arrows and stones that have basically buried the whole commune in fire and smoke. Based on the projectile of the arrows, the attackers must have hidden on the top of the mountains. Their commune was built in a valley hidden deep within Bukhansan. It helped protect them from natural disasters and from any curious passers-by, but what they had failed to expect was a disaster caused by human beings. The valley created an advantage for those who wanted to ambush them.

As most of the residents of the commune have left for the Temple, the arrows and stones have also stopped pouring down, but Kyuhyun cannot see anyone come down to the commune from the mountains. Whoever had made this attack tonight were clearly more comfortable with staging an ambush than a fair fight, so it might be fair to suggest that they know quite well what the Children of the Mountains are capable of, and that they would never win in a face-to-face fight.

As Kyuhyun continues to look to the top of the mountains, he can see more than twenty figures slowly going up to the top. It is in no doubt the twenty guards that he had sent to the mountains to find the attackers. Seeing that the attack has now ceased, he guesses that the attackers had either sensed the movements of the guards, or the guards had managed to fight them off. But even though the ambush on the commune has stopped, the aftermath is neverending. Kyuhyun looks at the houses on the side of the main roads that once were the most beautiful and resilient houses he has ever seen. Now what is left is only the rubble of the tragedy, and the ghosts of what the commune once was.

"Help! Help us!"

As Kyuhyun continues to inspect houses on the side of the roads, he suddenly hears a familiar voice calling out from the sea of fire and dirt in the road ahead. He quickens his steps, and before he knows it, he is in front of the training academy for the children in the commune. Outside the gate to the academy, Sol and Do sit with two other children, each consoling one child who is crying and screaming to be let inside. 

"What happened?", Kyuhyun voices his question as he quickly approaches the group.

"Master!" Sol's voice sounds more than relieved at the sight of her fearless leader. "Their teacher is stuck inside the school.", she turns to the two children still sitting on the ground, their faces covered in dirt and tears. "They would not leave without their teacher."

Kyuhyun turns to look at the three main buildings inside the school campus. All three of them have been swallowed whole by the same sea of fire that has terrorized Bukhansan tonight. Even the gate to the school is burning like firewood. Getting close to the gate at the moment would be near impossible, let alone getting in the buildings and searching for another person.

Kyuhyun stands there thinking for a while. Then, he gently turns to Sol and the other three children: "Take the kids to the Temple at the foot of the mountains. Sangho and the guards have already taken most of the survivors there." Seeing the unwilling eyes of the children, he smiles softly: "Don't worry. I promise to bring back your teacher to you."

"But, Master," Sol says worriedly, "the fire is too big in there. I don't think..."

"Don't worry, Sol." Kyuhyun repeats. "Just take care of the kids."

Sol knows whatever she says at the moment could not change her leader's mind, so she does as Kyuhyun told her to. She picks the kids up from the ground and slowly heads in the direction of the Temple at the foot of the mountain. When she turns around to see Kyuhyun for the last time, she could only see a dark and tall figure from afar standing in front of the gate to the school with his coat over his head, then, suddenly, that figure charges into the fire like a soldier confronting his enemy. Sol wants so badly to run after her leader, to follow him into whatever hell he will get himself into, but the words "Don't worry" keep echoing in her head like a song in a cave. She tightens her grip on the children, and quickens her steps on the path down the mountains.

Inside the yard of the school, Kyuhyun diligently searches for any sign of a human being. He repeatedly calls out the teacher's name, but hears nothing in response. This could only mean either that the teacher is not here, or he is unconscious inside one of the buildings. Kyuhyun decides to enter the building closest to him. The heat from the fire burns on his skin, and the smoke is suffocating. He thoroughly searches through the building, but finds no sign of the teacher. He quickly runs out of the building, gasping for air as if he has just been underwater for the longest time.

Kyuhyun turns to the next building and takes a deep breath before again entering the sea of fire. This building is even more badly burnt than the first one. Occasionally, a few pages from a book fly in the air before catching on fire and eventually burning to ashes. Just then, Kyuhyun realizes what this building is used for. It is the communal library, which stores some of the rarest books in Joseon in all disciplines from history, politics, martial arts, to folklore, medicine, botany, and so on. These books have been collected and kept safe by the previous leaders of the commune for hundreds of years, and now they are all burning in a ruthless fire that spares no beauty, no knowledge, and no wisdom.

Kyuhyun suddenly feels the urge to run to the bookshelves and take as many books as he can into his arms and out of the burning building. He immediately turns the corner that leads to the main hall of the library, on the way, he tries to collect as many tablecloths and curtains as he comes across. As soon as he enters the main hall, another scene makes him stop in his steps. A man wearing simple but neat dark-colored clothes is lying unconscious on the floor, his lower body stuck between the floor and a bookshelf. As Kyuhyun comes closer to the man, he can see traces of blood on his forehead and forearms, probably from the collapsing roof structure. 

"Han seonsaengnim!"

Kyuhyun recognizes the unconscious man as soon as he sees his face through all the blood and dirt. Although injured and bloodied, Teacher Han remains a tight grip on more than ten books, hiding them safely in his sleeves and his robe. Kyuhyun suddenly realizes that he had come here with the same purpose as him: To save those books!

"Han seonsaengnim!!"

Kyuhyun calls out his name again. This time, he hears a few coughs from the man. Then, Teacher Han slowly opens his eyes, still unoriented and weak from his injuries. 

"Mas... Master?" After a while, he finally manages to recognize the man sitting beside him. Then, as if he has now remembered all the chaos that has happened here in one night, and his purpose for coming to the building, he struggles to take out the books which he had hidden in his sleeves and robe and hands them to Kyuhyun.

"Master, save... the books. Take them and get out of here" 

Teacher Han's breathing is weak and uneven. Kyuhyun can only imagine the pain from being stuck under a heavy bookshelf. He shakes his head at the teacher.

"We will get out of here together."

He had promised the children he would bring his teacher back to them. He had promised himself no one else would get hurt in this chaos tonight. This man will not die here because he has run into their communal library to save their precious books. 

Kyuhyun gathers all of his strength to pick the bookshelf up from the floor. Not only is the bookshelf heavy, but the fire has also made it more difficult to take a good grip on the shelf. Kyuhyun feels his face completely covered in sweat and ashes. His wrists feel like they can come off any second now. Finally, Kyuhyun feels the shelf slightly move from the floor. He immediately puts more strength into picking it up, ignoring the pain in his arms and wrists. 

"Han seonsaengnim, how do you feel?"

As the shelf is taken off the teacher's legs, Kyuhyun quickly examines his injuries. He uses the tablecloths and curtains which he had just collected on the way to the main hall to cover the wounds and stop the bleeding. The rest of the cloths, he uses to cover the books and their noses and mouths to keep themselves from inhaling the smoke. Kyuhyun also puts two large pieces of cloth over his and the teacher's heads to prevent the fire from burning them. He carefully helps the teacher stand up and slowly, both of them once again run through the sea of fire that is swallowing the building whole. Occasionally, a piece of wood from the roof falls down around them, bringing with them the dirt and ashes from the fire. 

The way out of the building seems much longer than the way in. The fire burns ruthlessly around the two men, and every ten seconds, a piece of wood hits them from above. Finally, when they step foot outside of the burning building, both of them take a deep breath of the fresh air outside, and exhale in relief. 

"Master," Teacher Han suddenly notices a trail of blood on Kyuhyun's shoulders, "are you bleeding?"

Kyuhyun turns around to look over his shoulders and realizes a slight pain in his left shoulder. A piece of wood must have grazed him, and he is bleeding from the wound.

"I'm fine," Kyuhyun puts a cloth on the wound and turns to reassure the teacher. "Let's go."

The two men continue towards the gate of the commune, through all the burning and collapsed houses and the scorched farmlands and gardens. Finally, when they get to the gate, Kyuhyun takes a last look at the once peaceful and prosperous commune. A night breeze suddenly gives him a chill and throws his hair in a mess. He raises a hand to put his hair in place and realizes that his hand has been covered in blood and ashes. In only the span of one night, the home and shelter to thousands of people of the Children of the Mountains have gone up in flames and burnt to the grounds, destroyed beyond recognition. For a moment, Kyuhyun could only stare at the sea of fire that used to be a bustling street in the mountains.

"Let's go, Master." Teacher Han lightly tucks at his sleeve, "we'll be back later."

With his words, Kyuhyun is pulled back into reality. He turns to the teacher to put the other's arm on his shoulder, and slowly, the two men disappear into the dark and cold winter night, their hearts filled with grief that can never be put to words.