The Khitan emperor is about to lead a large army and cross the Yalu River to attack Goryeo.

The battle between Goryeo and Khitan begins in the middle of the night, and the people of Goryeo shiver with fear. With 400,000 soldiers, Khitan attacks Heunghwajin for seven days straight, but they are unable to destroy the fortress. Therefore, they come up with another strategy. Meanwhile, Prince Daeryangwon visits the temple where people are gathered to pray.

The Emperor of Khitan is infuriated as he loses the first conquest expedition he is leading. He starts advancing south with his army towards Samsuchae to destroy Goryeo's main force. Therefore, even though Officer Yang manages to defeat Khitan soldiers, the main force assumes Heunghwajin has lost the battle as they are trapped. Officer Yang must find a way to send the word.