The story begins during the War of the Roses in England, but our hero, Gervaise Tresham soon joins the Knights of St. John in Rhodes. Dedicated to God's service and pious in his personal life, Gervaise uncovers a plot, saves the coast of Italy from the Muslim corsairs, and is knighted by the Grand Prior. After being captured by and escaping from the enemy, the young English knight draws his sword in the defense of Rhodes. He finds himself in a tough position desiring marriage, but having taken a vow of chastity! In the end, it is the Roman pontiff himself that gives him the release he needs to wed.