Gisele is a girl born transparent, like glass. So much so that her thoughts are instantly visible. As a child, her negative thoughts helped her parents understand her moods and could readily intervene. Later in life, her thoughts get her in trouble and she leaves home. After years of searching and finding only rejection, she comes to accept her thoughts and comes back home.
General Note
"Originally published in French by Albin Michel Jeunesse as Gisèle de verre"--Colophon.