Silent explosions erupted along the fleet's perimeter, immense fireballs illuminating everything around them, followed by beams of every kind streaking across the void.
The Navy Guardsmen on the Bridge watched as the monitoring signals coming through the Auspex triggered shrill alarms.
Nearly two months of peace shattered in an instant.
The veil of the Warp was torn open once more, and an enormous fleet surged into realspace in a standard fan formation. Yet the markings on the ships astonished everyone.
"The Dark Mechanicum!"
The guardsman responsible for monitoring the battlefield on the Bridge shouted the attackers' identity.
The Imperial Ships, already on alert, immediately returned fire.
Guilliman, who had anticipated an attack, merely narrowed his eyes.
Repairs to the Rock Monastery had long since been completed, and the other ships had largely finished their refits as well. An enormous Imperial Fleet was making its way toward them through the Warp.
Guilliman and Lion El'Jonson had remained here precisely because they wanted to see what other cards that Daemon demigod still had up his sleeve.
Hellforged-class cruisers fired strangely colored blasts of Chaos Energy. Their savage silhouettes were sinister and terrifying, and the power of Chaos surged across their armor.
Defiler-class battleships angled their hulls, their dense broadside arrays of macro-cannons firing rapidly and hurling countless enormous shells at the Imperial Fleet.
Guilliman signaled the fleet to maintain formation and begin a slow retreat toward the edge of the system, while continuing to exchange fire with the enemy.
But events did not unfold as he had expected.
As the fleet began moving, dozens of Dark Mechanicum ships did follow. Yet after only a few dozen minutes, something went wrong with several Imperial cruisers at the rear.
They abruptly swung their guns around and opened fire on the other Imperial Ships nearby.