The official player’s handbook for the Beneath series. This guide has:
A full weapons list
provides maps of Craglee and the overall land
a list of "the missing people of CragLee"
an index of CragLee and what you do there
NPC illustrations and stats from The Inverted Church
It also has a new (not included in the main campaign book) 50+ page side quest full of maps, loot, and insane NPCs. The random dungeon generator on the back of the book mimics the Dungeon Dealer card system. This is a key mechanic in the side quest. You can also use Dungeon Dealer cards to generate random hallways --that's probably the most fun way to play this.