The ship shakes again around us, more fiercely this time. There is a ­scraping and a clattering that echoes up through the ventilation. The lumens flicker and for the dozenth time since our patrol began I put my hand to my sword’s hilt in the anticipation of a threat. Ashava tenses, and her hands move on the stock of the flamer she carries. Her new weapon, in the wake of Ophelia VII. But nothing materialises, and after a moment the noise and the shaking recedes back to how it was before. The sense of threat lingers, vaguely, as it has for days.

‘Adelynn was so right,’ Ashava says, easing her stance.

I nod, letting my hand fall away from the hilt of my sword. ‘So very right.’

Another noise echoes along the corridor then. This one is not violent, but melodic. A dolorous chorus of ship’s bells, set to mark the hour in Terran standard time.

‘Eight bells,’ Ashava says, when they have finished tolling. ‘I would have called it later.’

I shake my head. ‘I would not have known well enough to guess.’

In times long gone, there would have been a watchman on the ship who called out in the wake of the bells to let everyone on board know they were safe. But even if we had such a watchman, he would not have a thing to say because we are not safe, and nor is the Vow. Nothing is, while we are inside the Great Rift.

I activate my suit’s vox-link.

‘Hail, Sisters,’ I say. ‘What have you to report?’

The vox squalls for a long moment before my Sisters answer in turn from their positions all across the ship, where they are patrolling just like me and Ashava. Qi-Oh is first, because her pride permits nothing else.

‘Nothing to report from the starboard batteries,’ she says.

Sarita and Munari are next. ‘Nor the billets, Sister Superior.’

‘Or from the lowdecks,’ Calyth says, from where she patrols with Veridia and Joti.

The vox hisses again, and I see Ashava frown, but then Eugenia’s voice breaks through.

‘Labour halls reporting clear, Sister Superior.’ Eugenia pauses, and I hear her take a breath over the link. ‘Though I feel as though it is anything but. The people here are restless and unsettled.’

Qi-Oh scoffs over the link. I can almost see the derision on her face.

‘There have been riots in the past days,’ Eugenia says. ‘Murders, even.’

‘But nothing since you arrived?’ I ask.

‘No, Sister,’ she says. ‘Though I feel as if it is not for lack of wanting.’

‘It is the same here,’ Calyth says. ‘As though there is a pressure building.’

‘Exactly,’ Eugenia replies. ‘Or a great heap of stone, waiting to collapse.’

I glance around me, at the wavering light from the cherubim who fly but will not sing, and the slick, sweating walls of the spinal corridor.