Armageddon is wracked with war. As hordes of ferocious Ork warriors surge across the planet, they are met in combat by the combined forces of the Imperium. The bloodiest and most gruelling battles are fought within the hives: the ancient, towering cities that are the last strongholds of Humanity. Across Hive Acheron, elite squads of soldiers are deployed where larger armies are unable to operate. These guerilla fighters creep through the twisting pipes and gantries of the hive to strike deep within enemy territory. They are assassins, and saboteurs – they are the kill teams of Armageddon, battling over precious promethium in order to win the shadow war and decide the fate of the bitter battle that has engulfed the planet.