Deborah Mayfair was rescued at the age of 12 by Talamasca member, Petyr Van Abel, in the year 1664. Deborah was first seen at the location of her mother, Suzanne's, burning for witchcraft in the small Scottish village of Donnelaith. Conceived on the night of the May festival, she is considered a 'merry-begot' and her father is unknown, though rumors state the Earl of Donnelaith.
Deborah's mother, Suzanne, was the woman to first summon the being "Lasher".
Deborah is taken to Amsterdam to stay with the Talamasca, and on the journey young Petyr is enamored with this dark-haired, silent girl.
While in Amsterdam, Deborah becomes a favorite of the painter Rembrandt and soon married the artist Roelant. She rejects the Talamasca as evil and 'witches'. During this time, Lasher makes her wealthy by bringing her jewels and coins from around the world. With the money from Lasher, Deborah was able to buy the later infamous Mayfair Emerald; which is passed down to each female witch.
Roelant later died and Deborah later married the Comte de Montcleve from France. Before she leaves Amsterdam, she seduces Petyr and is soon pregnant with a child, Charlotte. As well as giving birth to Charlotte, Deborah also had sons: Chretien and Phillipe. Deborah became the village healer in Montecleve. She was spoken of well in the village and got a small name for her powers to heal. Later, the Comte is unfaithful to her and takes a fall from his horse (thought to have happened because of Lasher). On his deathbed, he states to his mother that his wife is a witch and told him secrets of her past. Deborah is unable to save her husband. The Comte's mother accuses her of witchcraft and purposely killing her son and Deborah is tried and found guilty.
Petyr hears the news in Amsterdam and travels quickly to France. They talk before her death: Deborah begs him to be far away from the village before she is burned, that he won't be safe. She will not allow Petyr to 'save' her.
In her final moments, as she was led down to be burnt at the stake, she summoned down Lasher, "Come now, my Lasher, be my avenger, strike down my enemies!" "I see you, Lasher, I know you! I call you!" "Destroy my sons, destroy my accusers! Destroy those who have come to see me die!"
Many in the village die, including Deborah's two sons (who have turned against her), the Comte's mother and the Comte's mistress. Petyr escapes unscathed and returns, heartbroken, to Amsterdam.
Deborah died in 1689 at the age of 37.