Kingdom of Goguryeo, ancient Korea, 645. The ruthless Emperor Taizong of Tang invades the country and leads his armies towards the capital, achieving one victory after another, but on his way is the stronghold of Ansi, protected by General Yang Man-chu, who will do everything possible to stop the invasion, even if his troops are outnumbered by thousands of enemies.
Soo-kyung works as a reporter. She has an older brother, Sung-ho, and younger sister, Joo-mi. She thinks of her two siblings as burdens. One day, Nak appears in front of them. He is their youngest sibling.
Daekwon is the team leader of the surveillance team on the verge of getting a demotion. His mission is to be as an unemployed head of a household and monitor the politician's family who's been house arrested right after arrival from abroad for 24 hours a day with his team. Members of the surveillance team, who have moved into the next door disguised as a neighbor, discover secrets one by one, through monitoring all the sounds and behaviors of suspicious family members, from requests for a radio show to midnight rustling noises…
