Zhen Yu received an anonymous package, which hinted at hidden truths about the explosion that caused his father, Zhen Jiangming, to die fifteen years ago. The clues were concealed within a hidden area of a game called "Just One Truth." Zhen Yu immediately entered the game and befriended three mysterious individuals: a girl named Bei Chen with an enigmatic identity, a mischievous and quick-witted person named Dong Ning, and a big-hearted and optimistic individual named Jia Xiaofei. As the four of them investigated the case, they all discovered certain mysterious clues related to their own pasts, and the truth became increasingly elusive.