Story follows a group of physical therapists, nurses, radiological technologists and trainees. Ye Jae-Wook works as a physical therapist and also teaches in the same field. He begins to work as a team leader at a hospital. Woo Bo-Young has been working as a physical therapist for 3 years. She wanted to become a poet, but due to her poor family background she studied to become a physical therapist. Shin Min-Ho is a trainee, but he isn't interested in physical therapy. His grades weren't good enough for medical school and his parents, who are both doctors, made him study physical therapy.

As a North Korean sleeper cell agent, Ryu-han infiltrates the South and assumes the role of a village idiot in a rural town. He observes the townsfolk and waits patiently for his mission. One day, after 2 years of playing the role of the village idiot, fellow elite spies Hae-rang, posed as a rock star and Hae-jin, posed as an ordinary student, are dispatched to the same town as Ryu-han. He helps the other two spies settle in and teach them how to adjust in the South. There is a sudden drastic political power shift in the North and all three spies receive an urgent and ultimate mission.