For the next three days, Cain sends out Dwarven Earth Mages as his Supporters, to help with the city wall rebuild. They've got a most excellent spell that can turn loose Soil into solid rock. So the plan is to have the Trolls dig a nice deep moat around the city, building up the walls and then have the Earth Mages smooth it out and turn the wall to stone.
Having a moat and the now necessary bridges to access the city is a huge win in the eyes of the Trolls. They never were skilled at construction, but they've always had a fondness for bridges of all sorts. The reinforced wall is just a bonus to them. Ten meters tall and thick with smooth outer sides the new wall is a formidable barrier. The deep moat connects to the nearby river from two spots, giving them a ring of slow moving water as a defense as well as emergency water supply for the city.
