In 2017, teenage friends Ji-hoon and Min-seok hide millions in stolen gold inside the concrete wall of an unfinished building before being arrested and sentenced to ten years in prison. When they are released in 2027, the construction site has become a thriving community, and they can no longer remember which wall holds the fortune. As they search the town under false identities, the two former criminals begin building honest lives and find themselves protecting the very people they call home.