War broke out.
Almost every Iron Warrior across the galaxy received the summons of their Gene-Father. The Warsmiths left the Black Legion and the Dark Mechanicum to gather at their father's side.
They drove their warships toward the distant Imperial Fleet in a mighty armada, with battle between the two sides imminent.
The Warsmiths lashed their daemons, firing shells with speed and unerring precision as they poured their fury onto the distant Imperial Fleet.
The Imperial Fleet fought desperately, but under the Iron Warriors' methodical assault, it fell back while continuing to fight.
Only when the cloud-piercing Planetary Cannon on Larsk opened fire and destroyed an entire fleet in the foremost battle formation did the Iron Warriors abandon their pursuit.
But that did not mean they were afraid.
Under Perturabo's personal command, an iron rain of Drop Pods descended onto Larsk, where they clashed with the Imperial Army on the ground.
Perturabo's tactical command was nothing short of genius. He processed hundreds of reports within moments and responded with precision.
Even if his decisions were exceedingly cruel.
Vast numbers of Slave Troops attacked under the Iron Warriors' goading. These armies, composed of Human Slaves and daemon engines, advanced at the point of the Iron Warriors' guns.
They howled as they attacked, trying to muster a little more courage.
But a moment later, a hail of bullets swallowed them. The Imperial Fists' War Fortresses gunned down the troops charging from every direction with unerring accuracy.
But that was precisely Perturabo's aim.
The artillery positions already in place roared, sending tens of thousands of tonnes of shells toward the distant fortresses.
The bombardment was so intense that cracks opened in continents with unstable tectonic plates. Surging magma erupted from beneath the crust, engulfing the artillery positions.
Yet the Iron Warriors stationed there