The pit of holo-light began to flare and boil. Su-Kassen began to syphon off information from the wider battle sphere, stretching her awareness out to the engagements around Mars, folding in the intelligence from Uranus, Neptune, Saturn and Jupiter.

The Solar System was ablaze. Battle data spiralled and multiplied as she watched. In places where there was need, she issued orders that would commit ships to battle; in others she pulled back what she could and watched the loss increments rise and rise. This was a war now measured in casualty estimates, lives spent by the thousand – because if they were not then what life would remain for anyone? This was her role, her duty, while Dorn turned his will to where it was needed, to the point where it could tip the scales of battle.

An alert light blinked at the edge of her sight from where the personal signal channel controls rose in a pillar of brushed bronze.

‘Admiral,’ said the officer a second later, ‘my lord Praetorian.’ She turned. ‘There is a ship closing at speed. It bears the clearance of the Lord Regent.’ Dorn was turning to look now, too. ‘It says that it brings someone you must see.’

‘Who?’ asked Dorn.

Battle-barge War Oath, Luna

The defenders knew the weapons of their attackers. The protectors of Luna, the veteran regiments, the ships of Su-Kassen’s fleets and the warriors of the VII and IX Legions knew that every thrust and manoeuvre of the assault had one aim: to allow the Sons of Horus to bring their legionary forces to bear on the surface and in the sub-surface warrens of the moon. Centuries ago, when the same Legion had spearheaded the conquest of Luna for the Emperor, the same had been true. The difference now was that Luna was not defended by the weapons of a gene-cult of Old Night, but by the arms and might of the Imperium. And those defences held the assault to the vacuum above.

Fire circled the moon. Rolling impacts struck void shields and peeled them back in flashes of light. Chains of plasma annihilators mounted on the Luna Ring spoke in sequence, one gun cooling while another poured sun-bright energy into the enemy ships. Swarms of bombers and interceptors spun amongst the fields of fire, thousands of tiny battles squeezed between exchanges that burned the dark like the fury of ancient gods.

Thirty Solar Auxilia bombers dodged through the grids of fire surrounding the Sons of Horus bombardment vessel Chieftain of the Red Blade. They were about to unleash their payloads just as a broadside struck the ship’s void shields. Arcs of discharge from the collapsing shields overloaded the bombers’ systems. They slewed off course, ploughing into the gun ports of the ship. Their payloads detonated. Fire punched into the Chieftain of the Red Blade’s gunnery decks and cooked off a macro shell being hauled towards a breech. Explosions ripped through the ship from the inside.