When faced with a minor invasion, the Imperium would often not respond to the attack at large, leaving the defending planets to fend for themselves. Over the millenia, several planets were lost to Chaos, Eldar, Dark Eldar, Necrons and as of late the Tau and Tyranids. One system was being attacked.
Oregon System, Eastern Fringe
Oregon Prime, designated Capital World
Currently under Tau invasion
The Tau's attack was brutal and efficient. Using some sort of new long-range phase artillery, they had managed to destroy the Navy garrison of two light cruisers and half a dozen escort ships before proceeding to commit to orbital bombardment. Half the system burned before advanced battlesuit squadrons and entire battalions of Fire Warriors landed on Oregon Prime in the midst of bombardment, forcing the various Planetary Defence Force and Imperial Guard units to desperately hold their ground and recapture a communications array to get support that was unlikely to arrive.
An armoured man watched the video feed of a Cadian stormtrooper, a Kaskrin, shout out the transmission while simultaneously firing at a target off camera.
'This is Trooper Arthur of the Cadian 242nd Regiment! The Oregon system is under major assault by an entire fucking Tau Sept, we need urgent assistance!' The trooper paused for a second to fire his hotshot lasgun. 'They're got possession of some sort of long-range artillery, destroyed our fleet and bombarded half the emperor-forsaken system.' The armoured man hit a button to stop the recording. He placed two fingers on his face and thought to himself. In the same room, one of five other people looked at the leader.
'You're in thought.' He deducted after a second.
'Hmph. The Tau are live-testing their new weapon developments on a lightly defended area.' The leader said after processing his thoughts.
'Lord Atreus, we'll be arriving on top of Oregon Prime in five minutes. Minimal resistance expected.' Over the vox, someone reported. Atreus inhaled and stood from his seat, feet shifting in power armour. The other Space Marine leaders stood up around the table, clad in their own variations of green and grey power armour. Three captains, a chaplain and Chief Librarian Quintin stood around Chapter Master Atreus Kadachi. Five of the leaders of the Shadow Monarch chapter of Astartes.
'Captains, once we've knocked out the enemy fleet, drop to the surface and secure the mainframe. Protect civilians. Chaplain Marius, accompany them. Quintin, you and I will be looking for the enemy command centre. Cut the head off, their progress will be considerably slowed.' Atreus ordered. 'Victory or death.'
'Victory or death!' The other commanders proudly shouted in the room.
Atreus tied his jet black hair back as he and Quintin walked down one of the battlebarge Claw of Medusa. The largest kind of ship deployed by Astartes chapters, battle barges were capable of transporting and deploying three companies at once. Medusa carried the chapter command, the 2nd, 3rd and 4th companies and their related vehicles and support equipment. Two Strike Cruisers, smaller ships meant to compliment the fleet, were carrying the 1st and 5th companies. This force represented 500 Astartes and a third of the chapter's manpower.
'Lord Atreus, auspexes are detecting a series of Tau warships centred around a battleship above Oregon Prime.' The same man on the vox from earlier reported. Atreus shrugged, putting on his Mark VI 'Corvus' pattern helmet. His looked no different from the normal kind except for heavy wear on the paint and metal.
'Focus on the flagship and larger escorts. Transports are of no concern.' Atreus shrugged his shoulders inside his armour as he and Quintin entered a teleportium chamber. Both were wearing jump packs. Much like their original chapter, part of the Shadow Monarchs's tactics revolved around quick, precise strikes.
'The enemy won't be expecting us to enter at such a close range.' Quintin said matter-of-factly, putting on his own helmet, the more classical Mark VII helmet with external vox-caster. His psychic hood covered the back area of his head.
'Exactly.' Atreus replied. He placed his hands on his weapons and unsheathed them. Both master-crafted. A power sword and a bolt pistol.
'Leaving the warp, five seconds.'
Atreus cracked his neck. 'Stand ready.'
Holding orbit over the planet, numerous Tau vessels stood in a cluster around one particular ship. The equivalent of a battleship. A pod underneath the centre of the vessel with a long barrel was firing down at the surface of the planet, pulsing blue with every shot. The balls of undiluted energy flew through the atmosphere and hit the surface to devastating effect. Slowly but surely, the Imperial garrison was being whittled down.
Claw of Medusa was about to stop that.
Without so much as a warning, the 10-kilometre long vessel appeared from the warp into realspace. To its flanks came the escorting vessels. The wash from the rift the ships were coming from tore some of the smaller Tau corvettes in half on their own. Claw of Medusa boosted forward, straight into the middle of the experimental battleship. It snapped like a twig, the middle buckling and exploding as its power core was compromised. The bow and aft of the ship fell to either side of the Medusa where they were demolished further by the lateral macro-batteries. The two strike cruisers, Fanged Sabre and Phantom Fury, engaged the Tau destroyers and frigates. Within the span of two minutes the Space Marine fleet completely devastated the Tau fleet. In the middle of all this chaos, the battle barge and the strike cruisers launched pods from bellies and Thunderhawk transports from hangars. They contained the reinforcements. Five hundred marines, fifty dreadnoughts and roughly a hundred vehicles. The Tau had overstepped their boundaries. They were about to pay the price for their deviancy.
Kasrkin Arthur shouldered his hotshot gun and fired a volley of high-energy lasers into the approaching Fire Warrior teams. Two days ago he and an entire battalion of guardsmen, 1000 men strong, had busted into a captured communications relay and sent out the request for reinforcements. The losses they had incurred while trying to get in were high. The losses they had taken when the Tau made their counter-attack were even higher. From 1000, the battalion had been reduced to 50, a handful of Kasrkin fireteams and commanders.
Beside him, a PDF member was hit square in the chest by a plasma shot. Arthur fired a burst at the offending Fire Warrior, destroying his cover and hitting the xeno in the head, before ducking down to check on the PDF guardsmen. The weapon had burnt straight through his carapace armour and into his chest cavity, killing him. Arthur cursed and stood up to fire again when he himself was hit in the abdomen, forcing him to one knee. A second shot to the chest in quick succession knocked him to the rubble that was the floor. Arthur groaned and looked at his wounds. Due to his better quality body armour, he was still alive, but wounded at that. Tau weapons were very powerful. A Fire Warrior squad approached the falling-apart position. One saw that Arthur was still alive, approached him and prepared to finish him off.
'Ave Imperator.' Arthur whispered to himself, fully prepared for his demise. There was a loud crackling noise and a burst of light. Arthur closed his eyes, waiting for the brief burst of pain and the following nothingness. That didn't happen. Instead there was a new outbreak of gunfire, sharp and brutal. The Fire Warrior next to the Kasrkin screamed as he was hit by something. The scream stopped near-instantly as he was hit by another round in quick succession. Its blood sprayed outwards, hitting Arthur. The latter frowned.
'I know that sound.' Despite his stomach and chest wounds, Arthur rolled onto his chest to see six heavily armoured super-soldiers firing with their collection of weapons into the advancing Tau warriors. This first squad was followed up by a second squad, identical in numbers and function. Space Marines. And judging by the storm bolter/power fist combo on the great majority, Terminators. 'By the Emperor.'
The two Terminator squadrons, quickly joined by another squad armed with melee weapons instead of ranged ones, wasted no time in supporting the surviving guardsmen and commanders by laying the wrath of the Adeptus Astartes on the Tau. Their bolt shells lanced through everything in sight. Fire Warriors, Breachers, Pathfinders, they were all turned into mush by the terminators.
A fourth squad appeared from thin air in the midst of the site. Arthur saw them appear. Although not well-versed in the tradition of a Space Marine chapter, he could tell that these Astartes were higher-ranking. One of the leaders, bearing Cataphractii-pattern Terminator armour, saw the Kasrkin on the ground and walked towards him slowly, shaking the ground with every step. His escort of Terminators followed.
'Guardsman Arthur.' The leader's voice boomed over integrated vox-casters. He recognised the guardsman. 'I'm Captain Torres of the Shadow Monarchs chapter. Where is your leader?'