In this article for History Today, I expose the secret weapon of the sixteenth-century Roman Inquisition: a new religious order called the Society of Jesus, also known as the Jesuits. Most people have only a hazy notion of the popes’ Roman Inquisition, yet many are confident that violence and fear were its main means of dealing with those who had erred from Catholic teaching. Interrogation, fires and torture were all very real elements of the inquisitors’ work; elements that struck terror into hearts across early modern Europe and persist in the popular imagination. But these fearsome tactics are far from the full picture. In this article, I show that the most useful tools of the Roman Inquisition were often Jesuit priests who used gentle, conciliatory, methods to turn minds and hearts back Catholic orthodoxy. Reputable, knowledgeable and devout, the Jesuits had a unique pastoral touch. When fearsome tactics failed, the Jesuits would prove to be the perfect good cops to Inquisition’s bad.