Sabbat Worlds: The Headstone and the Hammerstone Kings (Gaunt's Ghosts)

Heritor Asphodel died on Verghast, killed by the heroic Colonel-Commissar Gaunt, but his legacy lives on. In a graveyard of dead technology, agents of the Adeptus Mechanicus search for anything that can be salvaged and live again in service of the Machine God. But not everything in the graveyard is Imperial in origin. Some of Heritor Asphodel's famed and feared Woe Machines lie hidden in the dark, awaiting activation and the chance to wreak havoc in the name of the Dark Gods...

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In the Sabbat Worlds, an Adeptus Mechanicus team searches a machine graveyard for salvageable technology to help win the war. But not all the dead machines are Imperial in origin'