He dropped to his knees, hands pressed to his helmet as the Great Ocean tried to force its way inside his skull. He remembered his primarch’s warning and fought to keep it out.

Even in the desolation of Prospero, amid the ruined cities depopulated by the psychneuein, there was not this ferocity of psychic assault. Through tear-blurred eyes, he saw Astartes scatter, those without a connection to the aether spared the worst of the keening knife blade that gouged at his mind.

The ground shook as the first of the great machines took a ponderous step, its foot slamming down with seismic force. Lord Skarssen shouted at his warriors, but the words were lost to Ahriman. Ohthere Wyrdmake sagged against his staff, its haft swirling with coruscating arcs of black lightning. Beside him, Phosis T’kar and Hathor Maat fought against the corrupt power Magnus had warned them against. He couldn’t see Uthizzar or Khalophis.

Another shockwave shook the valley as the second giant tore free, the thunderous crashing of hundreds of tonnes of rock slamming down a forceful reminder of the physical world. Slabs of roaring red metal ground past Ahriman, churning the dusty ground with their passage; Land Raiders, their hull-mounted guns crackling with furious energies as they swept towards the Titans.

Ahriman felt a presence beside him and looked up to see Khalophis bellowing at his warriors. Astartes bearing the symbol of the scarlet phoenix moved to obey his orders, rushing to optimum firing positions and bringing their weapons to bear.

Ahriman wanted to laugh. What use would their weapons be against such war machines?

He tried to stand, but the pressure battering down his mind’s defences held him like a moth pinned to a slide. His resistance was locking his limbs together, fusing his joints with a stubborn refusal of the power that could be his were he only to let it in.

Ahriman recognised these temptation as the insidious whisperings that lured void travellers to their doom, as corpse lights had once ensnared those lost in ancient marshes.

That recognition alone was not enough to keep him from wanting to heed their siren song.

All he had to do was let it in and his powers would be restored: the power to smite these war machines, the power to read the currents of the future. The last of his will began to erode.

No, brother… Hold to my voice.

The words were an anchor in the madness, a lodestar back to self-control. He latched onto them as a drowning man holds fast to a rescuer’s hand.

Ahriman felt someone touch his shoulder guard, and saw Uthizzar standing above him like a priest offering benediction. The Athanaean pulled him around so that they were face to face. They gripped each other’s arms tightly, as though locked in a test of strength.

Rebuild your barriers, brother. I can protect you for a time, but only for a time.

Ahriman heard Uthizzar’s voice in his mind, the telepath’s measured tones stark against the raging torrents that threatened to overwhelm him. He felt a blessed quiet in his psyche as Uthizzar shouldered his burden.

Rise through the ranks, brother. Remember your first principles.

One by one, Ahriman repeated the mantras that allowed a Neophyte to control the powers of his being, easing into the energy-building meditations of the Zealator. Then came the control of the mind of the Practicus, the achievement of the perfectly equanimous perspective of the Philosophus. With every advance, the barriers protecting his mind were restored, and the furious howling of the aether abated.

Hurry, brother. I cannot shield you much longer.

“No need,” said Ahriman, as the world snapped back into focus. “I have control.”

Uthizzar sagged and released his hold on him.

“Good,” he said. “I could not have kept that up.”

Ahriman pushed himself upright, the world around him chaotic as the Astartes aligned themselves to face the gigantic war machines. Both were free of the cliff, the black tendrils enveloping them pulsating like newly filled arteries pumping strength around their bodies.

His situational awareness was complete. The Space Wolves had found cover in the huge piles of debris at the side of the valley. Ahriman was impressed. The Sons of Russ had a reputation for wild recklessness, but that didn’t make them stupid. To charge headlong into this battle would see them all dead, and Skarssen knew it.

The Thousand Sons had assumed the formation of the Nine Bows, an aggressive configuration of three warrior groupings named for the ancient Gyptus kings’ representation of all their enemies.

“He has gathered them all into his fist, and his mace has crashed upon their heads,” said Ahriman in recognition. Khalophis stood at the centre of the first block, Phosis T’kar commanded the second, Hathor Maat the third.

Geysers of fire spiralled around Khalophis, pillars of white flame enveloping him with searing light. Ahriman felt the enormous power surrounding the captain of the 6th Fellowship, its incredible potential bleeding into the warriors who followed him.

“Trust Khalophis not to take heed,” said Uthizzar, his voice scornful.

“He was not the only one,” said Ahriman, seeing blooms of aetheric energy centered on Phosis T’kar and Hathor Maat.

“Fools,” snapped Uthizzar, his stoic manner faltering in the face of such power. “They were warned!”

In the midst of the chaos, Ahriman saw Yatiri standing on the basalt altar, its gleaming surface splashed with the blood of his fellow elders. He held his falarica above his head and he was screaming. The winds from the cave mouth howled around him in a hurricane of corrupt matter, a blizzard of unnatural energy revelling in its freedom. At the centre of the hurricane stood Magnus the Red.

MAGNIFICENT AND PROUD, the Primarch of the Thousand Sons was the eye of the storm, a quantum moment of utter stillness. Though a giant amongst men, the soaring Titans dwarfed him, their towering forms still trailing thick tarry ropes of glistening black.

The first Titan inclined its enormous head towards Magnus, its alien mind picking out the primarch like a golden treasure in a junkyard. Its body shook with what might have been disgust, regarding him as a man might view a loathsome insect. It took a step towards Magnus, its stride unsteady and hesitant, as though it were unused to controlling its limbs after so long inert. The Mountain shook with the reverberative weight of its tread, yet still Magnus did not move. His cloak of feathers billowed about his body, the violence of the Titans’ awakening seeming not to concern him at all.

The machine’s enormous fist flexed and its arm swung down, the movement so unlike the monstrous, clanking machine noise of Imperial engines. A haze of electromagnetic fire vented along the length of its smooth gauntlet.

Then it fired.

A blizzard of slicing projectiles shredded the space between its fist and Magnus, a thunderous storm of razor-edged death. Magnus didn’t move, but the storm broke above him, shunted aside by an invisible barrier to shred the ground and fill the air with whistling, spinning fragments of rock and metal.

The enormous, lance-like weapon in its other arm swung around, and Ahriman was again struck by the fluid, living grace of the Titan. It moved as if its every molecule was part of its essence, a living whole as opposed to a distant mind imperfectly meshed to a mechanical body with invasive mind impulse units and haptic receptors.

Before it could unleash the destructive fire of the weapon, a storm of energy blistered its limbs. The Thousand Sons Land Raiders stabbed it with bright spears of laserfire, like ancient hunters surrounding a towering prey-beast.

The Astartes of the 6th Fellowship let fly with explosive warheads and storms of gunfire. Ceramic plates cracked and spalled. Fires rippled across the surface of the Titan’s armour. Imperial engines marched to war protected by shimmer-shields of ablative energy – not so this behemoth. Whatever protection it had relied on in life was denied it in this incarnation.