Stephen
Steven is an albino who was Argus's first apprentice. He was very driven, to a point of obsession with power. He had a nook in the basement he hid in to spend extra time studying, and wrote in the margins of books as a journal of sorts. Early in his apprenticeship, Steven blamed Argus for not teaching him enough. Eventually, he decided that his perceived weakness was not the fault of Argus, but his own weak Gift. He built a makeshift lab out in the woods now known as Gowdwin's Chase. He snuck books on Vim out here, and according to his own notes did secret experiments on his own Gift.
Agnes found Stevens nook during Spring Cleaning and through investigation found his hidden lab. A ghost intentionally brought her to the nook, although why no one is sure. Agnes also found out from Junior that Steven had lost his gift in his 10th year of apprenticeship, fled the covenant, and died. Peddler John, however, knew someone matching Steven's description had been seen around the nearby towns, and recently near the covenant. Agnes brought all of this information to Sandre, who has instructed Peddler John and Eustace to keep their eyes and ears open and see what else they can learn.
Having an apprentice lose their gift can severely damage a magi's reputation and Angus is quick to anger, so neither Agnes or Sandre has brought any of these discoveries to Argus's attention.