When strong-willed servant Huang Yu is wrongly accused during a Jinyiwei mission, she’s forced by stoic commander Lu Zhan to join the Northern Bureau as a constable. Gifted with a unique ability for solving crimes, Huang Yu uncovers shocking truths about her past. Amid perilous conspiracies and growing feelings for Lu Zhan, she rises from a humble maid to a fearless seeker of justice determined to clear her family’s name.