Complex sentence: The knights devise a plan to assassinate the malevolent ruler, but when the attempt on the King's life is foiled the would-be assassins barely escape and are on the run from an army they once served.
Split into simpler sentences: The knights devise a plan to assassinate the malevolent ruler. When the attempt on the King's life is foiled, the would-be assassins barely escape and are on the run from an army they once served.