Through an accident, Gao Yang time-travels back to the senior high school classroom of 2009. The tragedy of his past life is vividly before his eyes: tomorrow, Huang Bei's family will encounter a gas leak and be in mortal danger. Unwilling to leave any more regrets, before dawn breaks, he drags his desk mate and rushes to the scene at top speed, urgently contacting relevant personnel to break down the door and rescue them in time, saving the composing Huang Bei and her father, and rewriting a tragic destiny. Huang Bei is moved by Gao Yang, and romantic feelings gradually well up in the bottom of her heart. Holding the future opportunities in his hands, he lays out domain names and seizes the trends of the era. Facing childhood sweetheart Tu Xi's deep confession of love, he honestly refuses after the college entrance examination. Huang Bei is willing to disobey her family's arrangements and stay in Shengjing, while Gao Yang also makes a ten-day bet with his aunt.