Forrix watched the data strand from the Umbriel assault for a single second more, then let it dissolve back into the tide of symbols and numerals that cascaded before his sight. Across the entire sphere of the battle, Umbriel was but one amongst dozens of assaults, amongst hundreds of engagements, where counting losses on either side in anything less than thousands was meaningless. As First Captain and chief logistician of the Iron Warriors, he had lived every second of this operation as simulations spooled through the Iron Blood’s cogitators. The reality, even seen in the cold flow of symbols and numerals, was breath-taking.

Nearly four thousand primary-grade warships had already exited the warp from the Elysian Gate, pouring into the Trans-Uranic Gulf. They had paid for every kilometre advanced, but they had the coin in ships and firepower. They had pushed and pushed forwards, spreading out and advancing on the defenders not at a burning charge, but slowly, inexorably, like the erosion of mountains by ice. And just as mountains inevitably became dust, so this victory was assured. That was one of the things that made it beautiful.

Forrix’s current role was to control and marshal the forces still exiting the warp. That alone was a monumental task. For all the power they had brought to this battle already, there were still twice as many ships waiting in the immaterium. Normally, many of them would have been carried away in an etheric riptide or assaulted by neverborn creatures by now. But while storms were churning the warp, they had not touched the ships that came to make war under the light of the sun. The gods and their daemons – for even Forrix had begun to call them that – held back their hunger and spite from the warriors of the Warmaster.

Forrix heard the low click of pneumatics and looked to where Perturabo, primarch of the Iron Warriors, stood at the centre of the strategium. Pistons and layers of armour whirred as his gaze moved to a different cascade of hololithic symbols.

‘The condition update from the assault on Pluto is overdue,’ said the primarch.

‘Analysis of the battle-light from its orbits indicates an engagement on a larger scale than we predicted,’ said Forrix.

‘Than Aximand predicted,’ said Perturabo.

‘He still has enough main force to deploy that he should achieve domination within the required time.’ When Perturabo did not respond, Forrix said, ‘Something troubles you, my lord?’

The primarch turned his gaze on Forrix.

‘So far each of the strategic projections has held true. The intelligence from the Twentieth Legion has proven accurate, and where tactical reality is different, it is predictably so – the moving of main fleet forces from Neptune to Uranus, the lacing of the Plutonic Gulf with additional munitions. All of it is within a narrow band of cautiousness. We progress as we intended, and they respond as predicted. Everything is as predicted.’