Vedden rushed forwards, stepping over the twitching bodies of the speaker's bodyguards and picked up a weeping girl, no older than twenty and roughly shucked her over his shoulder. She screamed in pain and he slammed his fist into her face to shut her up.

His men formed a rough circle and he stepped into their midst.

'We've got what we came for: now let's get out of here.'

His armour was dented in a dozen places and blood ran freely from his temple as he pushed another screaming man from his path. Ortega tasted blood and its coppery stink reeked of failure. He had failed to stop the senseless murders of the demonstration's speakers, failed to keep the Emperor's peace and now all hell was breaking loose.

He heard the hollow boom of more shotgun blasts from the far edges of the square and despaired. He hoped that none of his troops had fired these shots, but if things were going to hell elsewhere as badly as they were here, then he could not discount the possibility.

Bodies pressed in all around him and he angrily shouldered them away. This could not last much longer, it was only a matter of time until they were overwhelmed and killed. He slammed another man aside as he heard a series of cough-thumps and suddenly white smoke was clouding up in billowing geysers.

Grenade canisters of choke gas fired from the line of judges at the palace gates landed amongst the crowd, spewing caustic fumes outwards in obscuring banks of white. The canisters were landing just in front and beside his group and Ortega made a mental note to thank whoever had given the order to fire them. He slammed down his visor, engaging his rebreather.

Through a gap in the choking smoke, Ortega espied the retreating squad of murderers.

Knots of stunned demonstrators stumbled aimlessly through the clouds of smoke, eyes streaming and chests heaving. Many vomited on the cobbles or curled up in foetal balls.

The noise was incredible, like a great beast had awoken and roared. Ortega knew they were in the belly of that beast. He sprinted after the architects of this carnage, weaving round stumbling workers and leaping the dead bodies left in the killer's wake.

Collix and the six judges he had hastily pulled from the line charged after him, similarly eager for revenge. He shoulder charged a man wildly swinging a huge wrench, his eyes bloody where he'd torn at them.

Then they were at the mouth of the approach street and he could clearly see the backs of the killers as they made their way towards a plain white building.

He yelled an oath and levelled his shotgun. The range was not good and he couldn't get a good bead with his visor down.

Virgil squeezed the trigger and one of the killers fell, clutching his shoulder. Collix also fired and scored a hit, but neither of their shots were lethal and the wounded men were dragged along by their comrades.

'Come on,' he shouted. 'Before they get into cover!'

Their prey skidded to a halt and formed a disciplined firing line. Ortega was surprised, but not so surprised that he didn't drop to his knees and brace his shield before him as their enemy's shotguns fired controlled volleys down the street. The shield rocked under a terrible impact, and a fist-sized dent appeared in the metal next to Ortega's head. But it held and screams ripped the air as demonstrators who had chased them down the street were hit.

He sprang from behind his shield, and was punched from his feet as a second, unexpected volley hammered into the breastplate of his armour.

Ortega granted, more in surprise than pain as he hit the ground. Collix rolled over to him.

'Sir? Are you hurt?'

Ortega groaned, and pushed himself upright and winced as he felt a sharp pain stab into his chest. The breastplate had absorbed the majority of the shot's impact, but it was holed, and blood streamed down its front. He was surprised at Collix's concern, but shook his head.

'Maybe a rib broken I think. Nothing serious.'

Collix hauled him to his feet and they continued down the street. Both men swore as they saw their prey dart through a thick, timber gate in a high wall that led into the grounds of a large town house.

Virgil Ortega jogged a few steps before he was forced to pull up short as the stabbing pain in his chest intensified. His vision blurred and he had to steady himself against the street wall. Collix turned.

'Come on, sir!'

'Go! I'll catch up,' he wheezed. Perhaps his wound was more serious than he had imagined. His breath heaved, a great sucking rasp.

He staggered after his men, casting a quick glance over his shoulder. There was no one else following them down the street, which surprised him, but he was thankful for small mercies. He took another step and closed his eyes as a wave of dizziness and nausea threatened to overcome him. His throat felt constricted and every breath felt like broken glass in his chest. He forced back the pain, biting his lip hard enough to draw blood and willed himself onwards.

His men had reached the gate the killers had gone through and Collix professionally directed them in breaching it. Two judges blasted its hinges as a third slammed an iron-shod boot into the lock, thundering the gate from its frame.

The roar of assault weapon fire blasted from the gateway, snatching the first judge from his feet. Collix and the others dodged back as another blast of gunfire raked through.

He lurched drunkenly up to his men, fighting for each breath and slammed his back into the wall. Collix risked firing his shotgun blind through the gateway and another hail of automatic fire sawed through in reply.

He dared a quick glance around the doorway, catching sight of at least four or five men with heavy stubbers, autoguns and a flame unit sheltering behind a sandbagged emplacement. Ortega swore. Anyone who showed their face in that doorway for more than a fleeting second was a dead man. A burst of gunfire fragmented the plasterwork around the gateway and he ducked back.

Collix and the others risked occasional shots through the doorway, but shotguns were no match for assault weapons and men who knew how to use them. A gout of fire spurted through the gate and the judges leapt back as the smashed edges of the frame were set alight, wreathing the entrance in flames.

Smoke and shadows danced around the street as cloudy tendrils of gas from Liberation Square oozed down the tributary street they occupied. Ortega thought he saw bulky shapes moving towards them, but his vision was blurring with pain and blood loss and he couldn't be sure.

They were at an impasse. To go forward was to die, but he wasn't willing to let these murdering swine get away. Another tongue of flame licked through the door, briefly illuminating the smoky street.

A shadow fell across Virgil Ortega as a massive form moved from behind him to stand in the entrance to the town house.

And the sandbagged emplacement disintegrated in a hail of thunderous gunfire. Flames whooshed through the gateway, wreathing an enormous armoured giant in a flickering orange glow.

Standing impervious in the flames, like some war-god of legend, a gigantic warrior in brilliant blue armour clutched a massive weapon that sprayed bolts through the gateway at a fearsome rate. Ortega's mouth fell open as he saw that there was not just one of these behemoths, but eight.

The giant turned its armoured visor to face him and he felt himself shrink under his gaze.

'We will take it from here, judge,' said the warrior, his voice distorted by his helmet vox.

Virgil Ortega nodded, unable to reply and waved his hand in the direction of the townhouse.

'Be my guest,' he wheezed.

Sergeant Learchus nodded in acknowledgement towards the wounded judge and charged through the burning doorway, his bolter spitting explosive shells ahead of him. Cleander was beside him and the other Ultramarines fanned out behind him, firing from the hip. The immediate threat was neutralised, the men behind the sandbags torn apart by massed bolter shells, but there was more assault weapon fire spraying from the upper windows of the building.