Choi Kang, a new resident of Changri-dong, clashes with youth president Kwak Byeong-nam over recycling issues. He then pursues a suspicious foreigner to clear up a misunderstanding, only to be threatened. During the chase, an unexpected incident unfolds.

Choi Kang is suspected of being a spy after a clash with a foreigner of unknown nationality. While tracking the foreigner's secrets with Kwak Byung-nam and Lee Yong-hee, he discovers an unexpected clue. This clue connects to Choi Kang's past.

A series of mysterious incidents unfold in Changri-dong. Choi Kang, Kwak Byeong-nam, and Lee Yong-hee begin to investigate the truth behind the incidents. The military attempts to cover up the situation, and someone is quietly watching the whole situation unfold.