From out of the void, a massive Space Hulk drifts into the Germannis system. As valiant Terminator marines of the Adeptus Astartes purge deck after deck, two of their number are captured by the sinister tyranids on the vessel. Lead the Emperor’s finest on a desperate mission to rescue their comrades and cleanse the hulk of the alien menace, or lead the implacable and Genestealers as they stalk their Imperial foes.