"The Spy Concubine" is the book that meets your needs.😋In the story, the female protagonist was sent to the emperor of the enemy country as a concubine. As the guardian of the secret of unifying the world, the female protagonist was involved in disputes time and time again, and she was good at medicine. She tried to use her own way to resolve the injustice of the country's destruction, and at the same time, she fought wits and courage in the harem. You can see the intelligence and courage of the female protagonist in the book,"The Spy Concubine", revealing the dark side of many harem struggles. I hope you like my recommendation, Mwah ~😗