Assault on Nightwyrm Fortress is a 4th Edition D&D adventure designed to take characters from 17th to 21st level. In this adventure, the PCs discover that not all souls rest easy, particularly those spirited away to Nightwyrm Fortress. To learn the truth, players must pierce death's veil itself and entre the Shadowfell, where sinister echoes of life wing through eternal gloom.

This adventure can be run as a stand-alone adventure or as Part Three of a three-part series of adventures (starting with P1 King of the Trollhaunt Warrens, and continuing with P2 Demon Queen's Enclave) that spans the paragon tier of gameplay.