The retired top assassin Xiao Ye, in order to evade the pursuit of the organization, took advantage of the car accident and explosion that caused Li Yan to lose her memory, and brought her to a remote border town. He falsely claimed that they were cousins. Li Yan, who was once arrogant and unrestrained, was forced to adapt to the life in the impoverished town. She often used her rich girl's attitude to tease about food and accommodation, but gradually relied on the tough and cunning Xiao Ye. Xiao Ye pretended to be coldly hostile towards Li Yan, but in reality, he silently protected her and sheltered her from the elements, repaired houses, changed medicine, and fought off harassers. He hid his identity as a killer to protect her. During their daily interactions, under the guise of the taboo of "cousins", the two secretly developed feelings for each other. Every approach carried a tinge of tension and ambiguity. At the same time, Li Yan's husband He Jun, in order to seize the inheritance, joined forces with Xiao Ye's old enemy Qi Meng (a former comrade who was in a coma) to chase to the town. He searched for Li Yan's whereabouts while launching a retaliation against Xiao Ye. The peaceful and secluded life was disrupted, and the two were forced to work together to deal with the crisis. They faced each other's identities and emotions in the tests of life and death.
