A drama about Cha Yeon-ho, a reasonable individualist from KAIST, and Min So-hee, a traffic investigation ace with cool judgment and warm sensitivity at the Traffic Crime Investigation (TCI).

Dreaming of making a way station for his sister and the villagers who have no choice but to commute along the dangerous train tracks every day, Joon-kyung sends many letters…

From a mountain peak in South Korea, a man plummets to his death. Did he jump, or was he pushed? When detective Hae-joon arrives on the scene, he begins to…