In the seventh season, after stealing some books from the Citadel's library, Sam confirms the existence of dragonglass on Dragonstone and writes to inform Jon. In the days that follow, Sam encounters a greyscale-covered Jorah Mormont among the sick in Oldtown. While the Citadel's Archmaester Ebrose considers the ailment incurable, Sam recalls a risky treatment developed by Archmaester Pylos that he believes may work in the early stages of Jorah's condition. Ebrose dismisses the idea and notes that the technique has been banned because it puts both the patient and the surgeon at risk. Spurred by the realization that Jorah is the son of his former Lord Commander, Sam performs the procedure in secret, scraping away the greyscale for good.
