Wu Yu, a math prodigy, and Tan Jiao, a mystery novelist, fall in love on a cruise but both suffer memory loss afterward. Wu Yu forgets the days following the trip, while Tan Jiao loses nearly a year and a half. After the tragic death of his sister, Wu Yu abandons his promising future to work as a mechanic in search of the truth. In his quest for justice, he crosses paths with Tan Jiao again.