Araghast's death did what the deaths of field commanders typically do to a force built around personal authority: it removed the organizing principle.
The Black Legion Chaos Astartes who had been holding positions throughout the monastery's ruins began to pull back immediately, their tactical cohesion converting from advance to withdrawal in a transition that was not quite panic but was not disciplined either. They moved toward exits that the Cyclone barrage had created in the outer walls, or toward interior sections where the fires provided cover, and they moved with the quality of people who have decided that the current location no longer serves their interests.
Gabriel and Orion were already waiting for that decision.
The combat team of fewer than ten that Gabriel had been managing since the outer engagement was positioned correctly for the withdrawal routes, and the element that made a nine-warrior team adequate against several times their number was the same element that had been true since the beginning: Orion's psychic output at full capacity, and Gabriel's hammer applied without hesitation. The Blood Ravens moved into the corridors and blocked the exits and the Chaos Astartes who had been pulling back found that the pull-back had been anticipated.
Nolan retrieved the warscythe from the floor and came in from the center.
What followed was conclusive rather than complex.
The last of them was Araghast's second: a Chaos Astartes who had commanded the reserve elements during the engagement and who had, as far as anyone could determine, contributed to the organization of the defense. He came at Nolan from the far end of a collapsed corridor, the quality of his approach being the approach of someone who has already decided how this ends and is committing to the decision.
The warscythe took him at the waist.
He fell in two sections, and the upper section caught itself on the rubble and stayed upright on the forearms, and the blood-red eyes in the helmet found Nolan with the concentrated fury of something that has converted its final seconds into a single purpose.
"Dogs of the Corpse King." The voice was ragged. "You'll find out what you've been feeding."
He looked up at the monastery ceiling.
"Ukel. The agreement is paid. The sacrifice is complete. Break the seal. Now."
He exploded.
Not outward: the blood and tissue that his body became did not scatter. It consolidated, drawing upward, collecting into the air above the point where he had fallen, and what it collected into was not cloud or mist but something denser, purposeful, the biological material organizing itself with intent.
And then the floor answered.
Everything the monastery's stone had been absorbing since before they arrived: the blood of Bloodletters and Plaguebearers, the remains of Black Legion Chaos Astartes, the viscera from Araghast's headless form, the fluid from every living thing that had died on this ground since the fighting started. All of it surged back up through the stone in a simultaneous release, joining the material condensing in the air, and the aggregate mass of it formed a sphere of biological matter thirty meters across that pulsed in the air above the monastery's central nave.
The sphere tore open.
The wind that came out of it was not meteorological.
It hit Nolan in the chest and drove him backward, the vibranium power armor's kinetic absorption working at a maximum that could not contain the full force, magnetic boots scoring across the ruined stone floor as he fought the vector. He drove the warscythe into the floor at arm's length and used it as an anchor, the blade biting through the stone and into whatever was underneath. The backward motion stopped after two hundred meters. He held position.
Around him, the Blood Ravens had been handled with less ceremony: the force differential between the wind and armored Astartes without a six-meter anchoring blade had produced the results physics suggested, and the Blood Ravens had found the walls and floors from distances that would require assessment before anyone could confirm which injuries were serious.
The Great Unclean One dropped from the air to the floor.
The impact of a Greater Daemon of Nurgle landing was its own geological event: the stone cracked, the surrounding rubble shifted, the fires in the burning sections of the monastery were briefly interrupted by the pressure wave. What settled from that impact was a body that defied the available categories: enormous, the green of deep infection, its surface a record of every disease that had ever incubated in the Warp's organic substrate. Pustules and cavities covered every surface in arrangements that held their own geometry. Two horns curved from a head that had once been humanoid in proportion and had long since moved past that limitation in every dimension.
The head turned.
The nasal cavity worked at the air, sniffing in a series of deep, appreciative inhalations.
"Fresh meat." The voice was deep enough to feel in the chest cavity before the ears processed it. "Bones full of chaotic vitality. Bile carrying the particular taste of approaching death." A pause, the sniffing continuing. "And something considerably more interesting than any of those. Something that Grandfather has been wanting to examine for a very long time."
The wet, filmed eyes found Nolan.
"One of the contractor's associates perished in fulfilling the arrangement, which is regrettable for them, but the agreement is complete regardless. And the presence of a Primarch is..." The vast head tilted slightly. "A bonus not anticipated in the original terms."
A sound emerged from the mouth of the Great Unclean One that was probably meant to be charming.
"Kneel, little Primarch. Grandfather Nurgle opens his arms very wide, and the welcome he offers is sincerely felt. The warmth. The community. The freedom from the particular loneliness of the uncorrupted."
Nolan pulled the warscythe from the floor.
He rose to his full height and looked at the Great Unclean One across the ruined nave with the expression he used when a situation had moved past the point where commentary added anything useful. His warscythe and Forgebreaker disappeared: pulled into the storage interface and replaced, for the moment, with nothing.
He looked at the vast green body for a moment.
"Ukel," he said. The daemon's name in his mouth with the flat weight of someone naming an objective. "Either you have been sealed under this floor for long enough that your reasoning has significantly degraded, or you have always been this poorly informed about how this category of conversation ends." He tilted his head slightly. "I have history with your brother Ku'gath Plaguefather, and rather more than history with Typhus who runs the Death Guard in Mortarion's shadow. Neither encounter ended in Nurgle's favor. The family reunion you're proposing has no favorable precedents from my perspective."
He raised one arm.
"Also. You are genuinely extraordinarily unpleasant to be near. That is not a factor in the decision, but it is worth stating."
The Volcano Cannon came through the storage interface on its vehicle chassis, the tracks finding the monastery floor and crushing it, the weapon's barrel already oriented. The barrel was long enough that even in the scale of the monastery's nave, it dominated the sight line between Nolan and the Great Unclean One at the far end.
Nolan put one boot on the vehicle's forward housing and stepped up.
Ukel opened his mouth.
Nolan activated the Volcano Cannon.
The beam that came out of the weapon was white at its core and moved fast enough that there was no trajectory to track: it simply departed from one end and was already at the other before any of the physical cues of its passage had resolved in the air. It hit the Great Unclean One Ukel at the center of the body mass, and it did not stop there. It went through, and the energy surplus that had nowhere to go escaped through the paths of least resistance: the eye cavities, the nasal passages, the mouth, the many apertures that Nurgle's gifts to this particular daemon had created in its surface over the millennia.
The Great Unclean One Ukel glowed from the inside, briefly.
The sound he produced was not one of Nurgle's catalogue of comforting sounds.