The Prince's Puzzle

A Prince, far from home and leading an army in a bloody civil war, meets a lonely lady. Her husband is twice her age and neglects her. The inevitable happens and the Prince unwisely puts his feelings for her into a series of letters. Then the unthinkable happens. She writes to say the letters are gone and the whole flank of the Prince's campaign is put in jeopardy because if the lady's husband sees the letters he will change allegiance to the enemy. They have to be found quickly and Captain Richard Croxall is dispatched to hunt for them. He has just three days but before the time is up blood will be spilled and people will die.