Originally, Defense Against the Dark Arts classes were held jointly for two Houses, but Cassius requested to teach each House separately, claiming it allowed him to better tailor his lesson plans to the characteristics of the students in each House.
Teaching was a matter for the professors, and Dumbledore, as headmaster, did not interfere too much. Besides, Cassius, being a high-ranking vampire, had no need for sleep; he simply had his Defense Against the Dark Arts classes scheduled at night.
Ever since the very first Defense Against the Dark Arts lesson, Camelia had noticed that this vampire professor seemed unusually interested in her, though it only filled her with irritation.
Chapter 38