Fang Zhu tries to persuade the Emperor to send him to lead the army in the impending battle with Leizhuo and to stop forcing Hai Shi to bring the mermaid, Lang Huan, back to the capital. Hai Shi overhears the conversation and decides to bring back Lang Huan to save Fang Zhu. The physician gives Fang Zhu a sleeping potion, allowing him to sleep for days. Poison is found in Ti Lan's food when imperial soldiers come to take Hai Shi's mother back to the capital. (Source: frankly at MyDramaList)