Tessa Cade is one of Defy the Night’s two teenage protagonists who, like her late parents, is an apothecary determined to heal as many people as possible, even if it means losing money or risking her own life. She steals from the wealthy and provides free medicine to those who can’t afford it. She is highly observant and intelligent, keeping diligent records of the people she treats and the slight alterations she makes to medicines. This is how Tessa makes medical discoveries beyond those of Kandala’s palace physicians—such as her dosage theory and unraveling of the Benefactors’ fake medicine.

Although Tessa has considerable knowledge and skill, many people don’t take her seriously at the beginning of the novel, due to her age, gender, and socioeconomic class. Most elites assume she couldn’t possibly know more than the older, formally trained palace physicians. However, her courage allows her to open up to Prince Corrick (whom she once knew as her crush and partner Wes) and share her “treasonous” theories with King Harristan. Ultimately, it is Tessa’s altruism which allows her to better understand the royals and become the bridge between them and the rebels. Neither party can succeed in ruling the kingdom alone, but with Tessa as a liaison, they’re able to combine their efforts and resources to start building a better kingdom for all.