The Kinnaree Conspiracy is set during the golden reign of King Narai in Ayutthaya, a time of intense trade and diplomacy, especially with the West. Tensions rise as foreign influence grows and local resentment builds.

Lady Pudsorn, the daughter of a renowned doctor, inherits her father’s medical skills. She crosses paths with Viscount Indra Ratchpakdee, a noble policeman, and Monsieur Robert, a charming Frenchman linked to the royal court. Together, they investigate the mysterious death of a French ship captain found wearing a royal-patterned sarong—clothing reserved only for palace women. The case threatens to spark war between Ayutthaya and France.

As they uncover hidden secrets and powerful suspects, including figures from the royal palace, both Indra and Robert fall for Pudsorn—who must navigate not only a dangerous conspiracy but also a complicated love triangle.