From the introduction: The flying galleon Thunderbound descends on Beregost, unleashing the wrath of the cloud giants! To save the town from annihilation, heroes from far and wide must awaken the lost machine entombed under Durlag's Tower. Dare you board the Ark of the Mountains and do battle in the burning skies? A 4-hour Epic Adventure for 1st - 16th Level Characters. User summary: Distributed as a 72-page PDF document and eight JPG files (maps and graphic play aids).