A field trip ignites Addie's desire to solve a centuries-old mystery: what happened to Lady Margaret Fraser? With the help of her older sisters Keedie and Nina, Addie begins her search for answers.

Addie and Audrey solidify their friendship when they go door to door to spread the word about the women who were wrongfully accused as witches. To heal the rift between her twin sisters, Addie plans a party for their upcoming birthday.

The Darrow sisters and Nina's boyfriend, Frank, go to the city in Addie's search for answers about Maggie's disappearance. While at the University library, Addie discovers some devastating information about Maggie's sister, Elinor.

Addie's mum accidentally invites Jenna to Addie and Audrey's slumber party. Addie reads from Lady Margaret's diary about her attempt to rescue her servant, Beth. Jenna questions Keedie on the rift between her and Miss Murphy.

Addie's fate at her school is decided. Audrey and Frank discover the amazing story of Lady Margaret's escape, inspiring Addie to make one final plea to the town for a memorial for young women wrongfully accused as witches.