The crew is working as fast as it can, but they can only move so quickly, or risk ruining it. The leading trolls seem to ahve been whipped into a frenzy by their leader, and charge through the wall, heedless of the danger. The first beast to make it through actually leaps over the barricade, admittedly straight down onto a line of spears, but the weight of the creature throws the men back, and breaks their line, just as more charge forward. The drain of channeling so much power, already, is starting to catch up with him, and keeping up the fire wall is taking more and more effort.<br/><br/>As more trolls crash into the wall, the catapults fire, lobbing the oil canisters into the charging army, splashing the trolls, and spreading the flammable substance everywhere.