I had, of course. Even now, Mizar was strained to the limit trying to pierce the gnarl-vine canopy, unable to distinguish disparate life signs in the festering waters. On a whim I drifted through the electromagnetic spectrum, the swamp in turn sparkling or growing dark as a tomb.

Something glinted.

It was some distance to our flank. A sickly pulse of energy that flickered like candlelight.

‘There… I see something,’ I murmured.

‘What is it?’

‘I am not certain,’ I said, squinting at the flickering light. It was unpleasant to look upon, like a grain of sand was lodged in my eye.

‘Is it below us?’

‘No. Some distance.’

‘Which way?’

‘Over there,’ I said, gesturing vaguely in the direction. As I did so I felt the bomber shift, Shard muttering something into the vox.

‘Is it ahead of us now?’

‘I suppose.’

‘Don’t suppose,’ she snarled. ‘You’re sitting in the navigator’s seat. Do a better job, for Throne’s sake.’

I flinched, startled. Her voice was hard, with an edge previously unknown to me. She turned immediately to the console, flicking switches and making preparations. I could just make out background vox-chatter as the vessels coordinated their positions.

‘Adjust five degrees to the left,’ I said.

She did so, and through Mizar I saw our escort do likewise. The formation seemed to be shifting, the Thunderbolts spreading out beneath us and accelerating.

‘How far are we from it?’

‘I… I don’t know how to judge distance at this altitude.’

‘Is there anything on the landscape?’

‘You see that bulge of vines? The mound with tumour-like tendrils?’ I said, pointing to the viewscreen. ‘Whatever I’m seeing lies in its shadow, on the side nearest us.’

‘Can you tell me anything else?’ Shard asked. ‘Do you see more than one light?’

‘No.’

‘How big is it?’

‘I… I cannot really describe it in those terms. The source might be the size of a candle, but its glare is blinding.’

I thought this answer might irritate her, but she merely nodded before asking a final question.

‘Is it stable?’

‘No. It flickers and flares, energy spilling from it. Is this craft rad-shielded?’

‘Yes. For all that it matters,’ she replied, gaze fixed ahead.

The vox flared again. Most of the exchange was meaningless to me. But Shard responded to each squad, sounding them by name and wishing each good fortune.

I did not find it reassuring, nor did I enjoy Flight Commander Nocter’s murmured prayer to the God-Emperor.

The light was drawing closer. I did not want to look at it, shifting my view to the surrounding planes, the Marauder bombers and the Thunderbolt fighters. One peeled off, almost dropping from the sky, its engines flaring as it descended towards the once-distant light. I could not think why, until I recalled Shard’s story of sending a lone Thunderbolt as bait for their guns.

As it did so, light flared.