After Nancy's friend George takes a job delivering prescriptions at the local pharmacy two customers become ill, and a third has died. As Nancy begins her investigation she receives her own prescription filled with danger.

Two customers have fallen ill, and a third has died after receiving deliveries from the local pharmacy. Nancy sets out to find out who is behind this case of sabotage.

When the customers of the River Heights pharmacy take seriously ill after being delivered their medicine, Nancy is convinced that sabotage is involved and searches for the deadly drug.

Nancy faces a bitter foe in pursuit of a venomous villain. #127

Nancy and Bess start hunting for an elusive suspect to save the Pennington Estate. Nancy's best lead comes from someone who wants to remain anonymous.

A two-hundred-old mystery puts Nancy in immediate peril.

Nancy mounts and investigation that leads to a series of dangerous encounters, an angry Doberman, a mystery assailant, and a life-threatening kidnapper.