The system of Fortion is located on the edge of the Eastern Fringe and is yet another battleground between the Imperium and the upstart T'au Empire. This turned from a five-year-long stand-off while the diplomats talked and bartered with each other to a wholesale shooting war last month after the slaughter of an entire Imperial delegation but the T'au who had invited them to their stronghold on the the system's capital world of Fortion Major which is a world divided between the Imperial and T'au forces which was to act as a neutral planet for these talks. Now, it is an all-out war zone with neither side holding anything back. Not wanting to risk the planet taking damage from their space war, Imperial Fleet Fortion and the T'au Fleet U'itoi pulled out of orbit and proceeded to have a running battle across the system, leaving their smallest ships at Fortion Major to provide orbital support for the war. Each side had agreed to keep no more than two thousand ships in the system. The Imperials are down to fifteen hundred, while the T'au are at thirteen hundred.
The peace talks were over, and there was only war remaining. Both sides have sent out calls for aid and were expecting it soon. So, in the middle of another engagement between their fleets, when both sides detected the Warp translation of a fleet of over five thousand ships, both attempted to find out where their loyalties lay. Both were horrified to find out that it was with neither of their sides. These ships belonged to the Orks. Neither side had yet heard of the WAAAGH Eternal or heard about the Sacking of Pylras Five, which led to the combining of two other WAAAGHs and at least three Ork raiding fleets. They have no idea that the Biggest Boss Killkrumpa Weirdblitz now rides at the head of an army of over two million Orks, all now broken down into two hundred Mobz of ten thousand like the Space Marine Legions of old. And then further broke them down to Chapter Mobz led by a new rank of Ork Nobz called a Supanob. All now leashed to the will of the Biggest Boss by Red, they are galaxies worst nightmare: Orks that follow orders and fight with military tactics. They don't know but they soon find out.
When the Warp portals start to open on the decks of the Imperial and T'au ships, vomiting Chapter Mobz onto the decks in the Orks are calling a Warp Walkin'. These boarding parties rampage through the ships, krumping everything in sight. They spread like viruses unstoppable, especially since they also introduce and actual virus in the form of Red into the systems of every ship on boarding. Each mob has members of the Mekka Korp in their groups who go directly to work, introducing their Pretty Lady into the systems. Red is more powerful than anything the Imperium or even the more advanced T'au can field. She burns through their ship systems and slaves them to her will. She opens every door giving the boarding mobz full access. They run wild, knowing that Red only cares about the ships; the crew is all fair game. Over the next four hours, a massacre that neither empire can stop begins as ship after ship falls to the Orks. Any who try to escape are hunted down and dragged back. A few heroic crews fly their ships straight into the teeth of the enemy, blasting their guns in suicidal charges that usually end in them being cut to pieces by Ork dakka, but some put their cores into overload before ramming an Ork ship, taking out both. This is usually the Imperium ships. The T'au just try to escape but there is no escape. Red wants them all.
In the middle of this fleet is the Space Marine Battle Barge Death's Pyre, belonging to the Marines Malevolent Chapter. Two full companies of the chapter were deployed to the Fortion System for these peace talks. A fact that hadn't gone over well with the delegates of either side. The Marines Malevolent do not have the best reputation. They believe in the eradication of every enemy of the Imperium and do not care how this is achieved. Often killing civilians without a second thought in the pursuit of this. The seventy-two remaining members of Squad Five are onboard Death's Pyre. They are boarding specialist and have been operating as such in this conflict. They are caught off guard by the Ork attack and listen as ship after ship screams for help as the Ork boarders overrun them.
The majority of Squad Five, including their Captain Castiel Sullean, had been on the arming deck when the attack began. Castiel, clad in his Terminator Armor flanked by members of First Squad, had rushed to the bridge. So, he is not there to witness the lone arrival of the Biggest Boss. Not known to hesitate, the Space Marines all do as the biggest Ork any of them have ever seen steps out of the portal, which snaps closed behind him.
"Ello there ya gits," says Killkrumpa as he pounds his four metal fists, "I heard you, boyz, are always looking for a scrap. Well, the Biggest Boss is here to give you the last one of your lives."
His fists crackle with Warp energy as he strides forward. The Marines Malevolent open fire.