This film begins with a monk controlling a dragon statue at a temple. The monk brought food and saw a child taking a nap in front of the statue. The monk teach martial art to the child. Twelve years later, Nguyên Vũ (the boy’s name) attacked the monk with a new moves. Nguyên Vũ confronted the guards for breaking the monk’s buddhist statue. Nguyên Vũ has a nightmare of his family being executed by that magistrate whom he just encountered. The monk told Nguyên Vũ that he is the grandson and the last family descendant of an official named Nguyễn Trãi. His grandfather has a mistress named Nguyễn Thị Lộ. The majesty gave them the title of a royal scholar. The majesty passed away and during that time Nguyễn Thị Lộ was by his side. His whole family got accused of murder and got executed. Nguyên Vũ asked the monk if he’s afraid of being affected since he took care of him. Nguyên Vũ read the word on the bottom of the statue “Innocent”.
Nguyên Vũ wandered on the street searching for the magistrate.Nguyên Vũ accidentally dropped some bamboo lantern from a stall, and the female owner Hoa Xuân demanded him to pick it up. Some Ninja fought with the king’s brother’s guards. Nguyên Vũ fought with the assassins. Nguyên Vũ hurriedly left. The king’s brother asked him if he’s scared he will hand him over to the court. He can tell from the birthmark on his hands that he is a Nguyễn Trãi descendant. Flashbacks of the prince uncle gave a tissue to Nguyên Vũ to wipe inks on his hands. Nguyên Vũ saw the magistrate talking to the king’s brother.
Nguyên Vũ wore a black suit and followed the magistrate. Empress Dowager and the magistrate discuss about finding the letter. Hoa Xuân fought with the guards outside of Empress’s Dowager’s hall.Nguyên Vũ helped Hoa Xuân fight. Nguyên Vũ suck out the poison out of Hoa Xuân’s leg.Nguyên Vũ stole a clothes from a female while she’s taking a bath,and left some money. Nguyên Vũ brought the clothes for Hoa Xuân. Hoa Xuân’s sister Hoa Hạ,came and spanked Nguyên Vũ . Nguyên Vũ said he can tell they are sisters since they always hit before asking. Nguyên Vũ and Hoa Hạ carried the bucket of poop which Hoa Xuân is hiding, and they walked out of the town gate. Nguyên Vũ asked Hoa Hạ why does Hoa Xuân wants to assassinate Empress Dowager. Hoa Hạ, explains twelve years ago, they had an older sister who crazily told people that the palace will be cover with blood. She got tied up on a pole on the sea and drowned and died. A guy named Vương Thiên rescued Hoa Xuâ and Hoa Hạ,and they found out that the death of their sister was under the Empress Dowager’s order. Vương Thiên failed in attempting to assassinate Empress Dowager. Hoa Xuân pushed Nguyên Vũ on the wall and made him promise to not tell about the poison incident. Hoa Hạ asked Hoa Xuân to forget their past and live a peaceful life.
The King’s brother said Empress Dowager’s scheme is to kill all the palace royals. He used to support one of his cousin to be the emperor but Empress Dowager used a dirty trick to eliminate his post. Rumors aroused that his cousin isn’t a royal. Nguyên Vũ asked if this incident is connected to the four blood letters. The king’s brother said twelve years ago that two royal eunuch are being assassinated on the way bringing the corpse the previous emperor to the palace. One of the eunuch wrote a blood letter about the scheme of the Empress Dowager but it landed on the hands of a prostitute.Nguyên Vũ asked the king’s brother if he ever suspected that Empress Dowager was the one who killed the previous emperor. Nguyên Vũ and the two sisters fought with the guards.Nguyên Vũ threw a sword on the pole and the lanterns fell down on the guards. They ran. Nguyên Vũ and Hoa Xuân hid in the wells. Hoa Hạ dies. Hoa Xuân impulsively wants to go to the palace. Nguyên Vũ slapped her. Nguyên Vũ told his identity to Hoa Xuân. Nguyên Vũ saw the dead body of a guard. He pointed to a cave. Nguyên Vũ followed the captain. The captain met with the magistrate. The magistrate held the legendary sword and demanded him to hand over the letter. Nguyên Vũ got stabbed by a guard in the woods. Hoa Xuân took care of Nguyên Vũ all night.Nguyên Vũ had a nightmare of Nguyên Vũ barged in the palace and threw a sword toward Empress Dowager’s body and she died. Nguyên Vũ grabbed the letter. A priest told Nguyên Vũ blood will drop out, and the letter contains blood. Nguyên Vũ woke up and worried that many innocent lives will be implicated.
Nguyên Vũ gave the letter to the king’s brother. Hoa Xuân feels being estranged from Nguyên Vũ. Nguyên Vũ peeked at the prince’s brother ordered the captain to kill all the royals in the palace and put the blame on the Empress Dowager and this blood letter will help him be the emperor. Nguyên Vũ barged in the room. Nguyên Vũ fought with the captain. Hoa Xuân pointed the sword at the king’s brother and demanded him the blood letter. The king’s brother killed Hoa Xuân. The captain punched Nguyên Vũ. Nguyên Vũ uses his wave power and pushed the captain.Nguyên Vũ threw a sword at the king’s brother and he died. The Empress Dowager has a dream of Nguyễn Trãi scared her at the execution scene. Nguyên Vũ came up to Empress Dowager and brought the blood letter. Nguyên Vũ hopes that Empress Dowager will stop killing innocent lives. The Empress Dowager ordered the guards to arrest Nguyên Vũ. Nguyên Vũ revealed his identity. Nguyên Vũ left.Nguyên Vũ don’t know what will lies ahead of him but he knows he and Hoa Xuân can start their lives over in a different world, a world without revenge.