The Doomstones Campaign part 2
From the back cover:
"Follow the century-old path of a renegade Orc warchief through the foothills of the Vaults mountains, discover the relics of a mutiny and a clue which leads to an ancient dwarven shrine and a second crystal of Power. Finding the shrine is just the begining - beyond lie age-old dwarven defences, and the tunnels' modern dwellers...
Blood in Darkness mixes investigation and combat to present WFRP players with a constant challenge. It is the second part of the Doomstones Campaign following on from Fire in the Mountains."
Later re-released, together with Fire in the Mountains, as Fire and Blood.