Marius Gage, First Chapter Master of the Ultramarines and at present Regent of Ultramar, gazed at the flow of people into the core of Spire Alpha.

These were some of the lords of Carenn. The rich and powerful, carrying whatever they could scavenge from their failing apartments, fleeing from a fate they couldn't yet comprehend. Gage didn't, either - the Emperor's Children, eleven months after Prospero, were wildly divergent from the Iron Hands, close as their Primarchs may have been.

The crowd funneled itself through a bridge between monolithic buildings; shouts of the trampling and the trampled were heard, but the Ultramarines kept a semblance of order. Gage himself stood on a pedestal in the bridge's center, directing the flow of refugees. The Hive cores were twice as heavily defended as the rest of Carenn put together, and the core of Spire Alpha was the sturdiest of them all. Gaius said he had initially constructed them to allow a last bastion of resistance. That was precisely their function today.

The dim, distant sun shone through the glass above the bridge. Gage watched it too, checking for any sign of trouble. There was none at the moment, signaling that, perhaps, Fulgrim's Legion was also checking its wounds.

Gage's helmet display showed just how deep those wounds were for the Ultramarines. Erikon Gaius was dead; Captain Lorchas, virtually so. The Ninth Company's leader was in a stasis field, having fallen in defending one of Spire Alpha's ramparts alone, against half a Company; reinforcements had come just quickly enough to rescue his body. If Gage survived this battle, he would commission a Dreadnought to be constructed for Lorchas - or, perhaps, use the shell from one of the Ancients that fell in the fighting.

There were sons of Fulgrim at Gage's side in this battle. They were members of the various Companies from the Third Legion, but they had - for whatever reason - turned their back on their Primarch. Gage found it difficult to trust them fully, but there were thrice as many of them as of the Ultramarines, and they were Astartes. Captain Krysander had told him that the Emperor's Children's organization had more or less collapsed, and that a hierarchy of torture and debauchery had taken its place; that seemed to Gage a sensible reason to betray one's Primarch, but the III Legion didn't fight in a disorganized manner.

There were sons of Fulgrim at Gage's side in this battle; there were none at his side on this pedestal. The civilians would easily be confused between friend and foe - Gage was confused between friend and foe! But this was natural in a war between brothers.

"They're mostly through! A couple more millicycles!" Ximeoden yelled from the bridge entrance. Gage nodded assent.

Even his bodyguards, he had been forced to scatter. But that, at least, was probably for the best; people reacted with less awe to him when he was alone. In a sense, even having a bodyguard was pretentious, though Gage knew he was important enough to warrant one.

Then again, so were many of these people, and now they were all fleeing in fear. Ultramar was bleeding against the power of a Legion.

"They're through!" Ximeoden screamed, as if he had no vox.

"Practical: prepare to seal the gates," Gage commanded.

"Already?" Taplon asked, via vox. "There are still refugees outside."

"There are also Emperor's Children outside. Theoretical: Most of the civilians outside the cores have already been killed or effectively killed by them."

Rage welled up in Marius Gage's hearts, both at the III Legion and at himself; but there was only so far he would go for the civilian populace, even if it was the civilian populace of Ultramar. So he only watched as, when the last stragglers had clambered onto the bridge, the first of two massive adamantium gates slammed down, crumbling some of the floor. The rest of it immediately engaged the defensive mechanism, and Gage ran against the human current, managing to get through the mass and around the gate before the second block dropped.

"Ximeoden! You locked Taplon in!"

Ximeoden shook his head. "There is the Kinme passage; and it has just become clear that we needed the gates shut immediately, because-"

Ximeoden pointed. And Gage saw.

They were as a violet serpent, crawling, all-consuming. The tower Gage and Ximeoden were standing in rose far above them, and stretched far below; but about twenty floors down, it expanded, leaving a square balcony ringing the spire.

Small lilac-armored Marines ascended through the ledge, some indiscriminately shooting at the buildings around them.

"How did we not notice them earlier?" Gage asked, even as he rushed to a gun. "Practical: it doesn't matter. Cover them with fire."

Twisting the launcher downwards, Marius Gage opened fire, even as Taplon entered the hall from the other side. Explosions pocked the metallic surface; a few Emperor's Children toppled over the railing into the void. Others crumpled down, heads ruined by the precise ammunition.

"Practical: Taplon, Ximeoden, hold the staircases. It'll be harder for them to use their numeric advantage in the narrow space."

A rain of fire continued to splatter the balcony, and Marius Gage wondered how it would've felt for the civilians living here to have the defenses hovering over them, a constant reminder that the galaxy was at war, that they were rebels. This was one of the strongpoints, but all the guns in the world weren't much use without men and women to fire them; at this point, Gage was alone.

Taplon came out of the control room, having turned the automatic guns to full activity. Below, one could hear the sounds of battle.

"Practical: the sentries are next to worthless against Astartes," Ximeoden noted.

"Practical: they're better than nothing," Taplon stated.

The first of the Emperor's Children burst up the stairs, straight onto Ximeoden's blade. The bodyguard's bolter took another one, and Gage stepped away from the siege cannon - the flow of Astartes from below had, at least, been ended.

Gage fired at yet another Third Legionnaire who was emerging, and then he was fighting alongside Taplon, even as the charges placed on the bridge did their work. Behind the Ultramarines, the path into the Hive core swung once, then twice, then not at all as it wobbled in its descent into the Underhive.

"Children of the Emperor!" came the cry from below. A bolter shell flew past Gage as he tangled with an Assault Marine. The III Legionnaire swung down, which Gage blocked before sliding up. Chainsword met powersword again, and then the other Marine slid backwards into his comrade below.

At the other staircase, Gage noted with peripheral vision, Ximeoden was down, dragged down by the sons of Fulgrim. Automatic guns continued to fire. Gage beheaded another of the Emperor's Children, even as another shot Taplon in the stomach at point-blank range. Alone, now truly alone, Gage knew he was doomed; their sensors' inexplicable blindness (psykers, probably, but when had the Emperor revoked Nikaea?) had been the end.

And then a plus grenade, from above. Gage dove for cover a moment before the charge exploded, filling the hall with shrapnel; behind it, Emperor's Children came down. But Gage recognized the unhelmeted warrior at their head, and as far as he remembered, Captain Krysander was on his side.

They clashed, brother against brother - truly brother against brother now - and Marius Gage leapt up, too, bleeding but not deeply wounded. He swung at the closest warrior, not bothering to read his armor, noting only the severed heads hanging from its pauldrons. It was spiked, too, but not in any useful sense; the spines were too short to serve as a weapon in battle. And they were rather odd for decorations.

Then again, lately the aesthetic tendencies of the Third Legion had been… unique. Gage had heard of the massacres perpetrated across Carenn, after all.

Melee exploded, sword against sword, bolters blazing with mediocre effectiveness; Gage's Terminator armor protected him from the worst of it, but it was hard to tell enemies from allies.

It was over quickly. Astarte-Astarte combat was typically brief, albeit bloody. On a red-tinted floor, Gage and Krysander, with some other Emperor's Children that seemed to be on Ultramar's side, watched the pile of corpses.

"We came too late," Krysander said.

"You saved my life," Gage noted. "Though you almost ended it with that grenade."

"A desperate measure."

Gage nodded. "Thank you, in any case. We seem to be holding?"

"My displays indicate likewise," Krysander said as the officers walked through the hall. "The Hive cores are sealed."

"Yes, and we have Marines in there. Theoretical: we have a chance."

And then, as the defenders of Ultramar came to the hall's eastern side - the one opposite the bridge - Krysander gasped.

He was standing on a balcony perhaps a kilometer away, hair waving in the wind, apparently delightedly tasting the view of ruin. His white cloak fluttered, and his perfect face seemed to suggest full satisfaction with the galaxy's state. His weapons were as grandiose as the Primarch himself, but he was almost armorless in the high-altitude wind.

"The Phoenician," one of the Children stated, apparently taking up Ximeoden's habit of stating the obvious.

And equally obvious was that, against this, against forty-five thousand more Space Marines, Carenn was doomed, though it would doubtlessly exact heavy payment for its fall.

Fulgrim turned and walked into the captured building.

The defenders of Carenn continued to stare.

The rain was failing, now, and out the window Gage could see Carenn's star coming into view once more. The cold light returned, here at the end. A pair of other Ultramarines ran in as Gage watched the city for signs of trouble. There were none; it seemed the Emperor's Children were making another pause.

Then Gage saw the Dreadclaws.

One by one, the drop-pods, tiny triangles in the vast distance, lifted off. Fulgrim was nowhere to be seen, and slowly, warily, Gage sheathed his chainsword.

"They're retreating," the Chapter Master commented. "They're breaking off their assault."

Krysander was silent.

"Theoretical: an assault would cost them many warriors," one of the Ultramarines present - Sergeant Stiridon - remarked. "Perhaps they didn't want to damage their Legion so."

"Theoretical: in a two-way war," Gage observed, "that doesn't matter. The destruction they sowed was massive, but they refrained at the very end, almost if - almost if this wasn't a two-way war. Almost as if there was a third faction."

"Xenos?" Krysander put forth, seemingly on the verge of tears.

"Or Fulgrim himself. There has to be a reason for this. They wouldn't do this to the civilian population for no reason."

"They would," Krysander said, and this time he shed a tear, or at least so it seemed through his gauntlets, which clutched his face. "You don't know them, Gage. They would."

"Yes," Gage said, rather frustrated at Krysander's unrestrained emotionality, "perhaps they would. They are savage weapons now, aimed at the people they should be protecting. In any case, they have killed many Astartes and even more baseline humans. The generators - "

The generators. The void-shield generators.

"Practical: orbital bombardment incoming!" Gage voxed to all Ultramarines on Carenn.

Erikon Gaius had counted on a traditional attack, with orbital bombardment coming first. But such a cover could be even more effective as a final blow, if the invader was retreating.

Gage rushed down, hoping to find a location where the spire's inevitable collapse wouldn't crush them all. The Hive cores themselves were well-protected, virtually safe from any fire from orbit; but Marius Gage was not in the Hive cores. Above, as Gage saw while he traversed the holed ledge he had been, minutes ago, bombarding, the sky was still cloudy.

He saw the first explosion in the distance from the Mid-Hive. The hallways were empty, but marked with flame-scars; battle had raged here. A corpse of Gage's co-Legionnaire lay nearby, under twinkling lights.

Then the spire shook.

Almost involuntarily, but aware that he was probably safe, Marius Gage walked over to a window. Above, hell was raging. Tall towers, sub-spires that had ascended to the frozen heavens, were toppling in crimson flames. Even as far down as Marius Gage was, the silhouette of the window-riddled and gun-covered towers, collapsing, grinding against each other, was visible against the white sky.

Plascrete rained into the Underhive, and as he felt Stiridon's hand upon his shoulder and saw the Sergeant behind him, Marius Gage continued the descent.

"Theoretical: the collapse won't get this low," Gage said. "Practical: it is still best to be as far down as possible."

"Civilians above?"

"Practical: dead. Or in the Hive cores."

Gage thought back to the sight of the sky-spires falling. The people of Carenn… many of them would survive this apocalypse. Perhaps even most. There had been warning, at least. The PDF had been useful too, at times, but by the final assault it had been virtually destroyed. Something had to be done about those humans' training; they had been cannon fodder for the Emperor's Children. Perhaps if Gaius had devoted more effort to them, rather than to the formidable physical defenses of Carenn….

It didn't matter. The people of Carenn had survived the invasion, despite heavy losses; the infrastructure had not. Once again, as in the Outer Sphere, Marius Gage felt hatred well up in him. Hatred - and determination, determination that the last word would be his and Macragge's yet.

"Practical:" Gage said, under a sky of blazing towers, "they will pay for this. They should never have left an Ultramarine alive."