General Kutuzov looked across his desk at the Imperial headquarters of the Mordecai Secundus campaign at the adjutant standing with the imperial psyker who had just delivered a bombshell to the general.
"Is there any physical evidence of this?" The general asked.
The adjutant looked across to the Logis Strategos adept who shifted on his feet a little before approaching the desk.
"Sir," the adept paused, his fingers nervously handing over the intelligence data slate. Kutuzov had a reputation for raging, but on this occasion the veteran general appeared calm. Nonetheless the adept seemed afraid of the information he was delivering.
"Analysis of enemy troop concentrations appear to suggest that there is a ring of forces being prepared around Kuneus. In addition there are Emerald Serpent forcess massing to the north west of the position. It appears as if something of great value is taking place at Kuneus, and that the forces of chaos are preparing for a massive attack. It is... Consistent, with my learned colleague."
Kutuzov stood, his height giving him added presence amongst those in his planning chamber. In the alcoves, several of his colonels stood and waited for his instructions.
"So, the traitors are planning a ritual. For what purpose we do not know, but it must be stopped. Have the astartes been alerted?"
"They have my lord", answered his adjutant, "but they are unable to respond at this time."
Quickly the general's eyes bore down on his colonels.
"What units do we have in the area?"
There was an awkward pause as the colonels looked at each other, as if waiting for someone else to take that question. Eventually the southern front commander stood forward, and cleared his throat.
"Sir, the only forces capable of responding in the timescale suggested are... The Librian 101st and 57th regiments."
The room fell silent. Least trusted in battle following the secession of the Librian system, and having a record as unreliable in combat, the Librians had been posted to rear areas and mopping up jobs. Now they alone could stop whatever ritual the chaos forces were planning.
Kutuzov briefly looked at the floor before addressing the room.
"So be it. And may the Emperor protect us all. Have an offensive drawn up immediately".
The Librian regiments near to Kuneus received their priority orders on 2405.020M42. Tasked with immediately advancing towards a location where they were told forces of the traitors were "planning operations which could have a deleterious impact on the campaign", the Librians were simply given orders to advance and take specific locations. Nothing of the ritual was mentioned. Colonel Jefferies dutifully planned an offensive and less than a day later the Librians moved forwards from their start lines.
The reaction to the advance was rapid from the Emerald Serpent, who deployed their elite Thousand Sons against the Imperial Guard, using arcane powers to teleport their forces around the battlefield as they were required. The imperial bombardment from basilisks and manticores was heavy, and the battle soon hung in the balance. Dropping in from orbit, Scions of the 51st reinforced the tanks and guardsmen on the ground as they advanced, taking many of the imperial objectives. However, the use of psychic powers meant the numerically inferior traitor astartes were able to react to each threat, and despite many of them being reduced to dust, the Librian 101st regiment started to take heavy casualties amongst the infantry.
The Librian tanks soon followed, showing once again their alarming predilection towards explosive conflagrations, as the imperial right flank began to collapse. Although the Imperium still had ample artillery raining down on the Emerald Serpent and had taken the objectives on their left, the overall advance stalled. Two days later, with their main objective still not taken, the Librians were appalled to see a great flash of light stream up from the land in front of them, streaking into the night sky far into the Mordecai system.
Two imperial transports were annihilated by this psychic emanation, but worse was to come. As the imperial fleet detected an energy spike which blew out all their sensors, the warp itself exploded into realspace within the Mordecai system. With a psychic shock that every living thing felt, a daemon world forced its way from the immaterium in an obscene mirror of birth. Astralis, daemon world of the Emerald Serpent had manifested itself in the Mordecai system. The Librian attack was cancelled.