The Earl of Clanranald, obliged against his will to attend a meeting of conspirators against King James (II) of England, is arrested. His death warrant is signed by the King and dispatched to Edinburgh by Sir Harry Richmond of the King's Bodyguard. Lady Katherine, the Earl's daughter, dresses up as a highwayman meets and later holds up the King's messenger. She receives a sword wound in her shoulder, but secures the warrant and burns it. Upon hearing her story, Sir Harry promises to do all in his power to secure the release of Lady Katherine's father.