Well to cut a long story short, the king was sieged by Duc Volpe(Wolf) and wants you to retrieve stone by a certain date. However there are bandits operating around the castle.
A challenging scenario, above all by an exact use of triggers, some of them conditioned ones. Thus, you could prevent them from happening for a long time if there wasn't a relentless time limit.
Bandits attack in enormous numbers. Unfortunately, the player has no chance to stop them on the harder levels without that trick, that non-restricted in-game measure Dianna125 has mentioned.