He fought two-handed, cleaving his blade through alien flesh, and bellowing at his warriors to stand firm as a seething tide of Laer surrounded them.

Striding through the shredded carcasses of the Laer, Marius Vairosean watched impassively as the warriors of Third Company gathered up their dead and wounded as they prepared to continue their advance. His stern face was lined with displeasure, though at who or what he couldn't say, for his men had fought as bravely as he would expect them to and Lord Fulgrim's plan had been followed to the letter.

With the landing zones and objective secured, all that remained was to link his forces with those of Solomon Demeter's Second Company, and Atoll 19 would be theirs. The cost of winning this victory had been damnably high: nine of his warriors would never fight again, their gene-seed harvested by Apothecary Fabius, and many others would require extensive augmetic surgery upon their return to the fleet.

The flaring pillar of energy that had been their objective was secure and he had split a detachment to hold it while they sought out Solomon's warriors, a hunt that might prove easier said than done. Explosions, gunfire and the blaring howls of the towers echoed strangely through the twisting coral streets of Atoll 19, and with the vox-network scrambled it was difficult to pinpoint exactly where the fighting was coming from.

'Solomon,' he said into the vox-bead at his throat. 'Solomon, can you hear me?'

Crackling static was his only answer and he swore silently to himself. It would be just like Solomon Demeter to have removed his helmet in the heat of battle to better experience the sensations of combat. Marius shook his head. What manner of fool would go into a firefight without all the protection he could muster?

The sounds of battle seemed to be coming from the west, though how to get there was going to be problematic, as the streets - if they could even be called that - snaked through the atoll in meandering paths that might take them kilometres out of their way.

The idea of setting off without a detailed plan rankled at Marius, a warrior for whom each advance and manoeuvre was planned with meticulous perfection and enacted without deviation. Julius Kaesoron had once joked that he should have been selected to join the Ultramarines, meaning it as a friendly jibe, but Marius had taken it as a compliment.

The Emperor's Children strove for perfection in all things and Marius Vairosean prized this striving above all things. The idea of not being the best made him feel physically sick. To be less than the best was unacceptable, and Marius had long ago decided that nothing was going to stop him from achieving his goal.

'Third Company,' he shouted, 'Move out on me!'

Instantly, his warriors were ready to move and formed up on him with parade ground precision, their weapons held at the ready. Marius led his men off with a ground-eating stride that Astartes warriors could maintain for days on end and still be ready to fight at the end of it.

The glistening coral walls of the city twisted and turned, fragments of crystal and stone crunching under their armoured boots as they made their way through the city. Marius kept following the path he thought best led to the sounds of fighting, encountering scattered bands of Laer warriors that fought with the desperation of a cornered foe. Each of these fights was easily won, for nothing could stand before the warriors of the Third on the advance and live.

He kept checking the vox for any word from Solomon, but eventually gave up on his fellow captain and switched channels. 'Caphen? Can you hear me. This is Vairosean. Answer if you can hear me!'

More static spat from the earpiece in his helmet, but it was swiftly followed by the sound of a voice, chopped and garbled, but a voice nonetheless.

'Caphen? Is that you?' asked Marius.

'Yes, captain,' said Gaius Caphen, his voice surging in the earpiece as Marius turned a corner into yet another twisting street of burrows and corpses.

'Where are you?' he demanded. 'We're trying to reach you, but these damned streets keep turning us around all over the place.

'The main arterial route towards our objective was strongly held, so Captain Demeter sent us and Thelonius to flank their position.'

'While he went up the centre, no doubt,' said Marius.

'Yes, sir,' said Caphen.

'We shall home in on your signal, but if there's something else you can do to mark your position, then do it! Vairosean out.'

Marius followed the blue dot projected onto the internal surface of his visor that represented Gaius Caphen's vox signal, though it faded with each turn they took through the maze of coral.

'Damn this place! No!' snarled Marius as the signal faded completely.

He raised his hand and called a halt, but as he did so a huge explosion erupted from nearby and a tall, curling tower of coral collapsed in flames not more than thirty metres to their left.

'That has to be it,' he said and searched for a way around the bristling lumps of coral. The streets wound away from the explosion, and he knew they would never reach Caphen by taking any of them. He looked over at the billowing black clouds and said, 'We're going over! Move out!'

Marius scrabbled up the face of a Laer burrow, easily finding hand- and foot-holds in the gnarled coral. He pulled himself higher and higher, the ground rapidly receding beneath him as he and the warriors of the Third made their way over the roofs of Atoll 19.

Ostian watched the first assault craft launch from the Pride of the Emperor with a mixture of awe and irritation. Awe, for it was a truly magnificent thing to watch the martial power of the Legion unleashed on an enemy world, and irritation because it had taken him away from the unblemished marble in his studio. First Captain Julius Kaesoron had sent advance word of the launch to Serena and she had immediately come to fetch him from his studio to a prime spot on the observation deck.

He'd tried to refuse, saying he was busy, but Serena had been adamant, claiming that all he was doing was sitting looking at the marble, and nothing he could say would persuade her otherwise. Now, standing before the armoured glass of the observation deck, he was heartily glad she had dragged him away.

'It's rather wonderful, don't you think?' asked Serena, glancing up from her sketchbook as her hand dashed across its surface, capturing the moment with astounding skill.

'It's amazing,' agreed Ostian, staring at her profile as a second wave of ships wreathed in the blue fire of their launch caught the sunlight on their steel flanks. The observation deck was hundreds of metres above the launch rails, but Ostian fancied he could still feel the vibrations of their release in his bones.

A final wave of Stormbirds launched from the other vessels of the Emperor's Children and he turned from Serena to watch them fly, birds of prey shooting into space like great darts of fire. Kaesoron had said that this was to be a full-scale assault and, seeing the sheer number of craft being launched, Ostian could well believe it.

'I wonder what it would be like,' said Ostian, 'the entire surface of a world covered by one enormous ocean. I can barely conceive of such a thing.'

'Who knows?' replied Serena, flicking a tendril of dark hair from her eyes as she continued furiously sketching. 'I imagine it would be like any other sea.'

'It looks wonderful from here.'

Serena gave him a sidelong glance and said, 'Did you not see Twenty-Eight Two?'

Ostian shook his head. 'I got here just as the fleet left for Laeran. This is the first world other than Terra I've seen from space.'