The events that led to the Wyvern Massacre were set in motion by Demona and the Captain of the Guard. Both were angered by the disdain with which Princess Katharine and her people treated the gargoyles who defended them nightly. They plotted to lure Goliath and the rest of the gargoyles away from Castle Wyvern, making sure they could not return to the castle before sunrise. The Captain would sabotage the humans' defenses, allowing the Vikings to easily take the castle. The people of Wyvern would be take captive and the gargoyles would be free to resume life as they had known it before their alliance with humans.
The plan went awry almost from the start. Goliath did not wish to leave the castle unprotected and pursued the Vikings with only Hudson. Fearing what the other gargoyles would think if they knew of her treachary, Demona did not warn any of her clan of the coming attack, instead leaving the job of protecting them to the Captain. She did, however, find shelter outside of the castle for herself before sunrise came. The Captain tried to defend the sleeping gargoyles, but Hakon did not trust his claims that the clan would not pursue his troops once the humans were gone. Hakon and his men shattered the stone gargoyles, all but destorying the entire clan.
A total of seven gargoyles survived the Wyvern Massacre. Goliath and Hudson discovered that the Vikings had created a diversion to draw them away from the castle, but were unable to get back before sunrise. The Trio and Bronx had been sent to the rookery earlier as punishment for an argument with some of the Wyvern citizens. Demona survived from her hiding place, but did not reveal herself to the others out of guilt for causing the massacre. By the time she returned, planning to say she had gone looking for Goliath and had been away from the castle at sunrise, Goliath and the others had all been turned to stone by the Magus.