The Emperor's Antidote

Faye Monroe and the crown prince, Julian, come to an exchange: she works on the poison in him, and he takes her medicines and tells her what they do. Before that he had her tested hard, on the assumption that the Empress Dowager had planted her, and she came through it. She had entered the palace as a maid to get near him. She had come down from her island to finish a book on a hundred herbs and was collecting cases for it. The poison in Julian is reckoned the worst there is, and it has left him weak and cold with the people around him. The Empress Dowager had been giving it to him. She wants the Seventh Prince on the throne, and the head maid of Julian's household reports to her. Faye and Julian also turn up something about his parentage, and he begins moving on the succession.