The brilliant seven-year-old Madeline "Matty" Matlock, who achieved success in her younger years, decides to return to the professional life of a prestigious law firm, where she uses her unassuming demeanor and cunning tactics to win cases and expose corruption within. Matty is assigned to Olympia, an older lawyer and rainmaker with a thirst for justice, while Olympia's ex-husband, Julian, the son of a company executive, takes an interest in Matty and his clever skills. Matty works with the firm's younger partners - the charismatic Billy and the ultra-ambitious Sarah - as he tries to settle into a new, high-stakes world.