(マーガレット・バートン, Māgaretto Bāton
) is a clumsy, absent-minded 19-year-old girl who attends an elite college for aristocratic families' children in Nafrece. Her memories of her own life are limited to its last twelve years, the word "Madlax", and vague recollections of something important connected to an unusual "picture book" she possesses.
Margaret is ultimately the
central character of the story, as she is the person who has the Gift
, a mysterious ability to alter the reality. Twelve years ago, she and the person who later became known as Carrossea Doon, survived a plane crash in Gazth-Sonika and interrupted the stand-off between Friday Monday, who unintentionally caused the accident while accessing the Sanctuary
(see Terminology), and Colonel Richard Burton, Margaret's father. Although Burton was victorious, Monday, with his last strength, chanted the Words of Awakening
and put him into trance, forcing to shoot his own daughter. Protecting herself, Margaret shot her father and, to flee from the guilt, used her Gift to split herself into three personae
: a one who retained the Gift, a one who took the sin of patricide upon herself, and a one who kept the memories of this. Since that moment, the person known as Margaret Burton became but a third of her former self, still possessing the Gift, but having lost all memories.
The "picture book" she has is Secondari
, the second of the Holy Books instrumental for using the Gift. Margaret believes that it was given to her by her father, though she cannot understand the language it is written in, or why some of its pages are covered with blood. The red shoes that help her remember about Secondari
are an obvious homage to Noir
, where a similar pair is worn by Kirika Yuumura.