A shadow passed over them. This was Eisenhorn’s daemon, surely. He didn’t want to look.

He did anyway, in time to see a massive orbital gunship pass overhead. It was moving so low it slammed through the upper branches of the tree canopy, showering down twigs and leaves. Its burners flared as it slowed and turned. The ground shook.

‘We need a clearing,’ yelled Nayl. ‘Medea can’t bring that in here.’

‘Two hundred metres that way!’ shouted Drusher.

‘Really?’ asked Nayl.

‘Well, maybe three hundred,’ replied Drusher. ‘I remember Fargul’s maps!’

They turned the way he had pointed and began to wade through the underbrush. Locusts still purred past their faces.

‘Keep going,’ cried Eisenhorn.

‘This is insane!’ yelled Macks.

‘Medea is telling me… keep going,’ Eisenhorn replied.

Overhead, impossibly huge and low, the gun-cutter swung around hard, attitude jets flaming. Nose down and lifting slightly, it moved back up the slope towards the Keshtre site.

Something was erupting up through the trees, pushing them down and splintering them back. Stone by stone, the walls of Keshtre Fortress were rebuilding themselves, rising up, pale and loam-caked, out of the old earth.

And something was climbing out of the fortress mound.

Something tall and slender, four times the height of any tree in the Karanines, rose up from behind the ragged curtain of stone. Then, a second, a third.

Drusher stared in amazement. He knew what they were. He’d seen them before. Seen them in a microscope field, magnified a thousand times so he could examine the joints, the chitinous cuticle structure, the black strands of hair follicles that sensed movement and vibration.

Spider legs. Some arachnid form, anyway. A xenos variety of chelicerata.

But these limbs were not under a microscope. They were two hundred metres long.

‘That’s not local,’ he said.

‘It’s not an arachnid either,’ said Eisenhorn.

‘A daemon, is it?’

‘A plague daemon,’ said Eisenhorn.

The joints flexed, the legs stepping up over the fortress wall, gaining grip to raise the body behind them. Imagination was no longer Valentin Drusher’s worst enemy. Imagination was woefully inadequate compared to this.

The world rattled. The gun-cutter had taken station and opened fire, hosing the fortress site with ordnance from its gunpods, chin-turret and underwing racks.

Fire bloomed in huge hemispheres, ripping up soil, splintered wood and fractured stone, five hectares of woodland laid waste.

‘Throne of Earth, that’ll flatten the whole world!’ cried Drusher.

‘No,’ said Eisenhorn. ‘Medea’s just trying to keep it at bay. To hold it back and buy us time.’

‘To do what?’

‘Reach the clearing.’

Drusher looked back, still running. The huge dark mass was rising up out of the smoke and raging flames that enveloped it.