Cassandra Clare said this quote

You cut me,” he said. His voice was pleasant. British. Very ordinary. He looked at his hand with critical interest. “It might be fatal.”Tessa looked at him with wide eyes. “Are you the Magister?”He tilted his hand to the side. Blood ran down it, spattering the floor. “Dear me, massive blood loss. Death could be imminent.”“Are you the Magister?”“Magister?” He looked mildly surprised by her vehemence. “That means ‘master’ in Latin, doesn’t it?”“I…” Tessa was feeling increasingly as if she were trapped in a strange dream. “I suppose it does.”“I’ve mastered many things in life. Navigating the streets of London, dancing the quadrille, the Japanese art of flower arranging, lying at charades, concealing a highly intoxicated state, delighting young women with my charms…”Tessa stared.“Alas,” he went on, “no one has ever actually referred to me as ‘the master’, or ‘the magister’, either. More’s the pity…