‘He killed him, didn’t he,’ said Za’tenga.

‘Yes.’

They reached the first descent, scurrying on hands and knees through the smoke-choked causeway. The second descent was sharper. At the front, Za’tenga nearly fell but Illion grasped the strap of his chest armour and righted him enough so the aspirant could regain his balance.

‘Gratitude, brother.’

‘Just keep going.’

Shuddering cracks, the wrench of stone splitting apart pursued them like a vengeful spirit as the causeway and the entire flank of the canyon started to disintegrate.

‘Move!’ Illion almost screamed, his eyes on Za’tenga’s back, feeling burning heat prickling the skin of his own. Lava crackled, the slow, deep snap of sloughing rock as it was dissolved in a glowing soup of immolation. A thick sheaf of the canyon wall slid away, crashing down amidst a rapidly expanding pall of smoke and blazing debris.

Illion was heading down, risking sure footing for a better chance of escaping the dissolution of the earth behind him. An ululating screech pierced the volcanic thunder and he stooped, not slowing, fearing a return of the mantarids. But the flyers were gone, fled beyond the storm and the hellish red clouds enveloping the canyon. It was the serrwyrms, burned away despite their chitinous armour. From his father Illion had heard of creatures on Nocturne, those of the low earth who could survive the lava lakes, even live in them, but serrwyrms were not that enduring. He gave brief praise to the Throne and Vulkan that at least one terror had been vanquished by another.

Now they merely had to survive the wrath of the mountain itself.

A second prayer of deliverance was quick to pass his lips.

After another fifty metres it appeared his supplication was answered when the aspirants reached a basin of ash and smouldering cinder, the pyroclastic leavings from the volcano venting above.

Kade was last to arrive, defying Illion’s hope that he had perished with the other predators. Behind him, most of the canyon wall had collapsed into a fresh sea of lava but the destruction had abated. Revelling in his survival, the Themian angled his head up to let the drifting flakes of grey-white touch his face. His laughter then was booming and terrible. As he looked down to regard the others, he looked like a ghost swathed in powdered bone.

‘I snapped his neck,’ he told them, the shotguns hanging by a strap over his shoulder an unspoken threat. There was no remorse in his expression, all the humour had faded too and a face of ice looked on at them. ‘Har’gaan was a dead man walking. His sacrifice meant we could live.’

For a moment no one moved or spoke, despite the fact that any delay could mean their deaths, and the rumble of the storm persisted violently in the void they had left.