In 645 AD, the Tang Dynasty’s emperor Li starts his invasion into Goguryeo, one of the ancient kingdoms of Korea. One victory after another, the Tang army marches into Ansi, protected by General Yang, the lord of the fortress. Abandoned by his country and outnumbered by thousands, the brave general gathers his men and women to face the Tang army on his own.

A former serial killer Byung-su gets diagnosed with Alzheimer’s and when a series of murders occur near his town, he worries whether the killings are his doings. Then, he comes across Tae-ju and realizes that he’s the killer. He reports this to the police, only to learn that Tae-ju is one. Byung-su tries to find evidence against Tae-ju, only to raise the young killer’s interest on him and his dear daughter.