<p>After an Adeptus Mechanicus research mission disappears without a trace on an ash-covered fringe world, a second team is sent in, led by the Tech-priest Enginseer Van Kullux and accompanied by a company of Astra Militarum. As they explore the darkness of ancient ruins, machinery begins to act erratically, and guardsmen and skitarii alike begin to disappear. Something slumbering beneath the ash has been unwittingly stirred from its great sleep.</p>