public. At the start of the novel, readers are introduced to the gravity of the crime that has occurred at the Château du Glandier, where Mademoiselle Stangerson has been assaulted while alone in her room, "The Yellow Room." The opening describes the initial chaos following the attack, as witnesses recount their horror and confusion. It sets the stage for Rouletabille's entry into the mystery as he engages with various characters, including the examining magistrate and the anguished Monsieur Robert Darzac, who is deeply connected to Mademoiselle Stangerson. Throughout this portion of the book, themes of danger, secrecy, and intellectual pursuit emerge strongly, laying the groundwork for Rouletabille's investigation into the inexplicable circumstances surrounding the crime. (This is an automatically generated summary.)