For Trooper Karl Grauss, there are no better fighting men in all of the Imperium than the vaunted Mordian Iron Guard. The epitome of martial discipline and grim determination there is no a foe that cannot best with force of arms… until the tyranids. In the rich and fecund surroundings of an agri-world, Grauss and his comrades make their stand. But against this voracious xenos breed there can be no victory and as the evacuation gets underway life is measured in minutes not hours. Can he survive long enough to escape the alien menace? Can anyone? 

It's a classic short story by Dan Abnett, plucked from the Black Library archives and presented as an eBook for the first time!