17th Century, Madrid. Abandoned at the doorstep of a monastery, Ambrosio has been brought up by the Capucin Friars. After becoming a friar himself, he becomes an unrivaled preacher whose sermons draw crowds and earn him the admiration of all. Admired for his extreme rigor and absolute virtue, Ambrosio is certain he is safe from any temptation. But Satan has not said his final word...