What do Théophile and Eugénie have in common in the novel, The Mad Women’s Ball?

Although the siblings are not particularly close, they share an understanding. Like Eugénie, Théophile is not free to choose his own path or future. Because he is cowardly and timid, he accepts his father's plans for him, largely without question. However, after his father locks Eugénie up at the Salpêtrière and Théophile does nothing, he becomes overcome by guilt. Over the course of the following weeks, he makes efforts to communicate with his sister, and he eventually becomes a key agent in her escape from the hospital.