Xu Yao time-travels to ancient times. She is the county's top charlatan, solving cases with just a tongue. Mo Chen is a down-and-out poor scholar. They make a three-chapter pact to become fake spouses, mutually not interfering in each other's lives. By day he plays the weak scholar, by night he is the Brocade Guard Commander; by day she plays the charlatan, by night she is a modern criminal investigation expert. Until the crown prince's treason case erupts, the moment he blocks an arrow for her, the sparks of love gradually bloom.