One day in the fall of 1938, a man named Harry Shier entered the operating room of a Toronto hospital and began an appendectomy procedure on a prepubescent boy. He was not a trained surgeon; he nearly botched the operation, and the boy’s parents reacted angrily. Suspicions about Shier’s medical credentials had already surfaced among operating-room nurses, and the hospital, aware of other complaints related to Shier’s groin-area operations on young boys, opened a formal investigation. By the time the hospital board determined that both his medical degree, from a European university, and his European letters of reference were…