From publisher blurb:
This groundbreaking supplement includes:
39 pages of lore, inspiration, and official details on the Dragongrin campaign setting
3 legendary new monsters (including a powerful “anti-dragon”!)
Invaluable information on three of the distinct locations within the world of Dragongrin
New unique, playable races, ready to dive into the ‘Vault!
18 adventure-spurring plot hooks
Unique new familiars from another plane of existence
3 unique and powerful magic items to spice up your game world
Roll tables to create your own legendary weapon
New organizations, complete with lush history and backgrounds
Deepvault is an ancient and massive sentient tunnel system in the world of Dragongrin, created by the Titans as a refuge for their most precious technology and knowledge. The vault was sealed eons ago, and the Titans are believed to have retreated into its depths to one day emerge to create a new beginning after the Oldest War. Deepvault has now been opened, and the power of the long-dead Titans has been unleashed.
Deepvault: Machinations of the Ancients is a thick slab of gonzo fantasy, marinated in magitech sci-fi, and grilled over a smoldering bed of Tabletop Terrors charcoal. It's a little weird, a little mad, and a whole lot of awesome.