A clever twelve-year-old housemaid who works at the Amwell estate and becomes involved with Nella’s apothecary shop, developing a significant bond with the women in her life.

A 32-year-old farm administrator from Ohio who travels to London on what was supposed to be her anniversary trip, unintentionally discovering a historical mystery involving an apothecary while dealing with personal marital issues.

The wealthy mistress of the Clarence estate who becomes entangled in the apothecary's affairs out of a desire to influence her husband's extramarital relations.

Caroline's husband, whose infidelity and subsequent actions significantly impact Caroline’s life decisions during her visit to London.

A helpful employee at the British Library who assists Caroline in her research into the history of the apothecary, becoming a supportive friend in the process.

The gentle and patient mistress of the Amwell estate, who has a nurturing relationship with Eliza but harbors darker intentions in seeking justice for wrongs done to those she cares about.

The predatory master of the Amwell estate whose actions catalyze critical events in the novel, painting a picture of the dangers faced by young women in the household.

A wealthy man engaged in an affair that leads his wife to seek clandestine means of influence, inadvertently setting off a chain of events with unintended consequences.

Lord Clarence’s mistress, entangled in the explosive fallout of the Clarence family’s personal entanglements.

Nella’s former lover, whose deceit and actions drastically alter the course of Nella’s life and inspire her turn towards darker practices.

A former housemaid at the Amwell estate whose tragic story is often recounted by the other characters, highlighting the brutal realities for women of her time.

The shopkeeper of a magical bookstore who becomes Eliza's first romantic interest, later playing an important role in her life and future.

The enthusiastic leader of a mudlarking expedition on the Thames, who plays a crucial role in introducing Caroline to the mystery of the apothecary vial.