Hammer and Shadow: The War for the Kaladruns is a regional and racial sourcebook for the Midnight campaign setting, detailing the holdfasts of the dwarves in the Kaladrun Mountains.

From Fantasy Flight Games' website:

Determination and defiance in the face of the Shadow.

A century ago, the forces of darkness overran Eredane and subjugated all its peoples to the will of the dark god Izrador. Almost.

In what remains of their mountain holdfasts in the Kaladruns, the dwarves still resist. It has been barely a dwarven generation since the Shadow fell, and living dwarves still remember freedom. They have the finest weapons and armor on the face of Aryth, traps devilish enough to kill a thousand orcs, and a legendary stubbornness in the face of adversity.

It is not enough. Every day in the world of Midnight the dwarves are losing their war against the numberless servants of Izrador. Hammer and Shadow includes:

• Dozens of forces, NPCs, and location descriptions for the Kaladrun Mountains and the armies that assault them.
  
• Maps, adventure hooks, and local rumors to incorporate into any Midnight campaign.
  
• New feats, prestige classes, charms, and equipment for both the brave defenders of the Kaladruns and the savage minions intent on destroying them.