Modern food blogger and history graduate student Su Xiaotang time-travels to the Great Liang Dynasty, becoming a rough chores servant in the manor of the Seventh Prince, Xiao Jingzhou. Just as Xiao Jingzhou fakes his death and lies low, Su Xiaotang, who stumbles upon the secret, gets dragged into the vortex of power struggles. Relying on her modern historical knowledge, logical thinking, and criminal investigation perspective, she forms an alliance with the Seventh Prince who plays the fool to avoid disaster, joining hands to investigate the unjust case of the Northern Border Su Family Army from nine years ago. The two confront rival prince factions, break through layer-by-layer tests and crises, uncover the mastermind behind the scenes, and kick off a well-matched mutual sprint toward each other, while the old case still leaves suspense behind.