Crash depicts the story of the Traffic Crime Investigation Team (TCI), which tracks only car crimes such as insurance fraud, retaliatory driving, self-harm blackmail, leka, call jump, and autonomous driving. Cha Yun Ho, a rational individualist from KAIST, and Min So Hee, a traffic investigation ace with cool judgment and warm sensitivity, track unusual traffic crime cases with the traffic crime investigation team to uncover the truth behind them.