Diem : For the moment Diem is the youngest member of the Dauzet family. Unlike her cousins, Vidette and Vidal, she is pure and good-natured. She is a lonely child and recognizes the sensitivity and sadness in others. She strikes a close friendship with Arabelle, the Professor's partner, who is also very much alone.

Throughout the story Diem tries to hold things together, being only six years old, she runs into countless challenges; her father's lack of attention, her cousins constant destruction, and Arabelle's heart break. Diem helps Arabelle as she tries to finish the work that she and the Professor started.