In the cold darkness of space, the tyranids travel from world to world, consuming all in a futile attempt to slake their hunger for bio-matter. Lying directly in their path is the industrial planet Tarsis Ultra, where Captain Uriel Ventris and the Ultramarines stand shoulder to shoulder with brother Marines from the Mortifactors Chapter. Uriel must accept the barbaric traditions of his allies and act against the ancient tactics laid down in the holy Codex Astartes in order to destroy the alien menace!