The tech-priests of the Adeptus Mechanicus eschew the weakness of flesh, preferring to show their faith in the Omnissiah by replacing their organics with machine parts. As well as religious, this is practical – disease can't affect the machine… or can it? On the agri-world of Dundas II, Tech-Priest Viridan Shale is dealing with a deadly outbreak brought to the world by the Death Guard. Nothing is safe as the contagion affects flesh and metal alike. With both biology and machinery under threat, she must find a way to defeat the plague and survive. The arrival of Iron Hands Space Marines – who similarly strive to overcome the weakness of flesh – may prove key to the world's salvation… if they are willing to aid Shale and her allies.