As war erupted between the Star Army and the Imperial Combined Fleet in the Manda Galaxy, the other nineteen systems were simultaneously struck by the Imperium's counterattack.
The First Fleet under Mendeleev faced the siege of several companies from the Mantis Warriors and Black Templars, both participating in the Indomitus Crusade, along with several other Chapters.
Mendeleev, several Space Marine company captains, and the Defense Force commanders were all under immense pressure, having to oversee the war across four systems at once.
The Second Fleet under Gray also clashed with a combined fleet of the Carcharodons Chapter, the Imperial Navy, and the Adeptus Mechanicus.
The main force of Gray's Second Fleet, consisting of twenty-two capital ships, faced more than a hundred capital ships from the Imperial Combined Fleet. The moment the Imperial Combined Fleet entered the Posilia System, it launched a ferocious assault on Gray's fleet.
Gray's Second Fleet was immediately placed at a disadvantage and could only hastily mobilize two patrol fleets, thirty-two warships in total, to hold back the fleets of the Carcharodons Chapter, the Imperial Navy, and the Adeptus Mechanicus.
The Second Fleet's other three detachments were likewise suffering counterattacks from the Imperial Combined Fleet. Gray and the others did not dare withdraw any ships to reinforce them and could only wait until they had determined the outcome against the Imperial Combined Fleet before providing support.
The main force of Dorak's Fourth Fleet faced the Imperium's Brass Dragons Chapter and dozens of Imperial Navy warships.
The Fifth Fleet under Mo Tuo faced enemies no less formidable. They had encountered the Minotaurs Chapter, along with a great number of elite Imperial Navy warships. The enemy came on with overwhelming force, like dark storm clouds pressing down upon them.
Like the other fleets, Mo Tuo's Fifth Fleet was at