A constellation of spheres and discs turned in the space above him, its outer elements spinning wide enough to almost touch the curved walls. The whole chamber was a sphere itself, eighty-one cubits in diameter, cut by telekinesis from a single block of jade. No living hand had ever touched its surface, or polluted it with memory. The spheres and coins of the solatarium at its centre moved on psychic currents. Most represented the physical Solar System, but others, principles no less real but ultimately intangible, spun beside them: Strength Ascendant, the Justice of Winter, the Crow’s Flight. The smaller spheres and discs were made of rock, metal and bone taken from the planets, moons and void bodies that lay within the light of Sol. Each planet was a sphere of crystal formed in the warp by will alone and brought into reality by sacrifice. When the final component had been set in place, the resonance had created a delicate shriek that had killed the last of the eighty-one psychic craftsmen who had made it. Since then, the sound of its turning had ached through Ahriman’s mind even when he was not in the chamber. It had been a vile price to pay, but there would be worse yet. Of that he was certain.

Ahriman and Ignis floated through the arrangement on silver discs. Both of them would leave as soon as this reading was complete. Out beyond its curved walls, the Ankhtowe plunged on towards its goal, moved by the half-lost science of machines. But in here, as the Sea of Souls fled past, they were standing still, looking out upon a growing hurricane. Only Menkaura would remain in the solatarium throughout the ritual. The War-Augur sat on his own disc, which hung upside down, relative to Ahriman, next to the golden sphere of the sun. Tarnish had spread across the silver of the disc, and Menkaura looked ragged and half-dead. The lacquer had peeled from his armour, and rust scabbed its plates. His head was bare, and the empty sockets of his eyes glowed with ghost-light and wept pus.

The sound of a diamond quill tip scratching on glass broke the quiet. Ahriman looked over to where Ignis was marking a line of calculations on a sheet of obsidian. The Master of the Order of Ruin looked up, the geometric tattoos on his face sliding into a new pattern. Ahriman sent a whisper of query by thought. In the solatarium chamber every thought was a shout, every sending a scream.

+The progress overall is within the calculations supplied by the primarch of the Fourth and his warsmiths,+ replied Ignis. +There are errors in the specifics that will need to be compensated for in the numeration of the final formulation.+

+That is what happens when plans touch reality,+ sent Ahriman. +Things fall apart.+

Ignis blinked, the patterns reforming again on his face as he considered the statement.