Modern girl Lu An accidentally travels back in time to the ancient deep palace, disguising herself as the imperial eunuch "Little Jiu". Burdened with a double-agent mission, she navigates and survives between various factions. Young Emperor He Mingqi accidentally acquires the supernatural ability to hear inner thoughts, repeatedly catching glimpses of the palace's undercurrents from her complaint-filled inner monologues. Moving from mutual probing to a tacit alliance, the two break through obstacles step by step and reverse their fates amid the treacherous palace intrigues, staging a lively and amusing light palace comedy.