The holy site will be attacked by an army of northerners. Before the attack you will have a choice between building palisades for defense, scouring the grounds for some items or recruit some poorly equipped zealots to help you in the fight.
30% chance: You will have an option to sally forth and ambush the enemy forces. If you choose to do so, you will fight two weaker waves of northern forces one after another.
30% chance: Allied southern forces will offer support. You can either ask them to flank arbalesters劲弩手 or infantry to reduce their respective numbers or order them to stay with you.