Minerva & Narcissa
"The Dark Arts encompasses all magic which intends to do harm," Minerva replied, no amusement in her features as she spoke. "While I believe there are some who are capable of studying the subject without implementing it, we both know it can lead some susceptible individuals down a path of no return. I certainly agree that you should restrict any experimental spells from those unstable characters." Narcissa was a bright enough woman. There was no need for Minerva to make a direct reference to Bellatrix.
"And let's not forget which house has produced the most," she retorted curtly. "As I said, Mrs Malfoy, your concerns are justified. However, it would be a matter for the board and headmaster."