Seraphina Linden transmigrates into a book, becoming the 'useless' daughter of the Linden Family, forced into a substitute marriage with the notorious playboy Julian Chua. With her super strength and modern knowledge, she makes money, deals with relatives, and trains Julian. From enemies to partners, they expose a reborn antagonist's conspiracy, stand against a prince, and reverse the General's Manor's cannon fodder fate. They find love and a happy ending.