Jiang Changhe, who repaired cars for more than twenty years, worked as a security guard in Yunwan City for six years. One afternoon, a couple drove home, but from the abnormal tires and the driver's shaking hands, he sensed danger and immediately sounded the alarm to lock down the residential area. Faced with the residents' accusations, colleagues' dissuasion, and a series of emerging doubts, Jiang Changhe persisted in investigating. Behind the seemingly ordinary sedan hides a past event related to a lifeline. As lies are peeled back layer by layer, can he find the truth before the crisis spins out of control and safeguard the safety of the entire residential area?