In the grim darkness of the far future, there is only war.
The Immortal God-Emperor of Mankind sits upon the Golden Throne, an icon, a beacon, a deity to humanity. The citizens of the Imperium of Man, over a million worlds, worships the God-Emperor. For over ten thousand years He has protected the Imperium against countless threats. Barbaric aliens, traitors who worship evil, and the many horrors of the galaxy. Thousands of wars are waged throughout the Imperium. The Imperial Guard, consisting of billions of brave men and women, countless tanks, artillery and aircraft, fight back against those who would exploit, enslave or devour humanity. The Emperor's own Angels of Death, the most elite warriors of the Imperium, genetically enhanced, armed with the most powerful of armors and deadliest of weapons, once lead by the Emperor's own sons, the Primarchs. These Space Marines are entrusted with the most dangerous missions against the many foes of the Imperium.

But without the Adeptus Mechanicus, the Priesthood of Mars, all of the armies of the Imperium would grind to halt. The planet sized factories, Forge Worlds, fuels the war machine of the Imperium, constructing tanks, munitions, armors, all that would be required. These Engineers are not only builders, but also explorers, scientists, and warriors if need be. The Mechanicus being so powerful, so different, that some consider it an allied empire rather than an organization within the Imperium of Man. Rather than worship the Emperor, the Techpriests of Mars worship the Omnissiah, the Machine God. In the tens of thousands of years that the Imperium has stood, countless technologies has been lost to time and war. The Mechanicus reveres these pieces of technology from a lost age, seeing them as holy relics, rather than simple tools. To enforce the will and to defend the Forge Worlds, countless legions of cybernetic warriors, the Skitarii, stand ready. And when the armies of the Imperium and Mechanicus are not enough, the Titans. The Collegia Titanica, a branch of the Adeptus Mechanicus, commands colossal war machines, dozens of meters tall and carrying enough firepower to annihilate entire divisions of warriors. These Titans are ancient, revered, and jealously guarded by the Mechanicus.

The current state of the galaxy is one of despair. In the 42nd Millennium the vast Imperium of Man has been split in half by The Noctis Aeterna, the Blackness. A cataclysmic rift that has broken the boundaries between our galaxy and the dimension of The Warp, where the forces of Chaos and countless daemons lie. It spans the entire galaxy, dooming entire star systems to death, terror, and enslavement. The legions of Chaos, traitor Space Marines, Imperial Guard, the Dark Mechanicus and its corrupted Chaos Titans, all have spilled out to destroy in the name of their dark gods. On another front a race known as the Tyranids threatens the Imperium. Aliens from outside of our galaxy, organic, armored in chitin, with claws sharp enough to rip through tank armor, weapons that spit bio-plasma, acid and hooked tendrils. The Tyranids surge towards Holy Terra, where the God-Emperor sits upon his golden throne, the capital planet of the Imperium. The Tyranids consume all life in their path, leaving behind hollow husks of worlds once teeming with life.

But not all hope is lost. Roboute Guilliman, one of the Emperor's own sons, a Primarch, has been resurrected. He now leads a vast army across the stars, reinforcing the depleted warriors of the Imperium, breaking sieges, and fighting back the countless invaders to bring back hope. It is called the Indomitus Crusade, and with every passing day, Guilliman and his warriors fight to secure the Imperium of Man.

Forge World Ferrox, located on the border of Segmentum Solar, the core worlds of the Imperium, and Segmentum Tempestus, the southern region, is under threat by the Tyranids. Hive Fleet Leviathan has sent a tendril of ships to destroy Forge World Ferrox in order to starve the armies nearby of munitions and repairs. Under threat, the Forge World has unleashed its Titan Legion, Legio Viribus, the Iron Disciplined. The Imperium and Mechanicus, knowing that the tendril has to stop on the nearby world of Chemasto, has sent their forces to the planet. Forge World Ferrox has sent out a call for help and trusted friend of the Mechanicus, Inquisitor Zhevon Amoxa, has promised reinforcements and a way to destroy the Tyranid tendril entirely, but he is still weeks away. Legio Viribus, assisted by a dozen regiments of Imperial Guard, an army of Skitarii and the Imperial Navy have entrenched themselves, waiting for the Tyranids to come, and hoping that the Inquisitor and his reinforcements come swiftly.