The Worms Beneath This is an adventure for Four Against Darkness -- a dungeon crawl through a collapsed castle and a maze of tunnels, to discover the reason why Castle Marrath collapsed and the fate of the nobles who lived there. 20 pages PDF, including 6 new magic items, 12 new spells (for druids and wizards), 18 new monsters. Suitable for a party of any level. Only the core 4AD book is required to play.