Sophia Dorothea spent many days talking to her eldest son in the library, and was informed of his plans to escape from his father's custody. In August 1730, during a tour he made with his father through the provinces, crown prince Frederick made an unsuccessful attempt to escape from Prussia, and was brought back a prisoner. The king informed the queen of the event through Sophie de Kamecke before their arrival. There were compromising letters by the queen and princess Wilhelmine in Frederick's portefeuille, which was forwarded to them by a friend after the arrest of Frederick's accomplice Katte. They burned the letters and replaced them with fabricated and uncompromising ones. However, "as there were near fifteen hundred of the originals, although we worked very hard, not more than six hundred or seven hundred could be completed in the time". The portefeuille was also filled with ornamental articles. When the portefeuille was later opened, Frederick did not recognize its content. Grumbkow immediately suspected what had transpired and stated: "These cursed women have outwitted us!"