Pyeong-yang-seong plot
At the beginning of the eighth century, Silla, a rising kingdom on the Korean peninsula, attacks the great kingdom of Goguryeo with the help of the Chinese. Goguryeo was until then the strongest kingdom and even a potential threat to the powerful Chinese Tang Dynasty. Kim, a military strategist from Silla, discovers that after the fall of Goguryeo, the Tang plan to attack Silla itself. Although Kim works with the Tang, he secretly conspires with the Goguryeo to keep the Chinese at bay. A sequel to Hwangsanbul (Once upon a Time in a Battlefield) from 2003.