was just the right size for us? It could have come from a human building.’
‘Then why are they getting smaller?’ Childe asked.
‘I don’t know. But I think Hirz is right. And it does worry me.’
‘Me too. But it’ll be a long time before it becomes a problem.’ Childe turned to the Ultra. ‘Forqueray — do the honours, will you?’
I turned and looked at the chamber ahead of us. The door was open now, but none of us had yet stepped across the threshold. As always, we waited for Forqueray to send his float-cam snooping ahead of us, establishing that the room contained no glaring pitfalls.
Forqueray tossed the float-cam through the open door.
We saw the usual red stutters as it swept the room in visible light. ‘No surprises,’ Forqueray said, in the usual slightly absent tone he adopted when reporting the cam’s findings. ‘Empty metallic chamber… only slightly smaller than the one we’re standing in now. A door at the far end with a frame that extends half a metre out on either side. Complex inscriptions this time, Celestine.’
‘I’ll cope, don’t you worry.’
Forqueray stepped a little closer to the door, one arm raised with his palm open. His expression remained calm as he waited for the drone to return to its master. We all watched, and then — as the moment elongated into seconds — began to suspect that something was wrong.
The room beyond was utterly dark; no stammering flashes now.
‘The cam—’ Forqueray said.
Childe’s gaze snapped to the Ultra’s face. ‘Yes?’
‘It isn’t transmitting any more. I can’t detect it.’
‘That isn’t possible.’
‘I’m telling you.’ The Ultra looked at us, his fear not well concealed. ‘It’s gone.’
Childe moved into the darkness, through the frame.
Just as I was admiring his bravery I felt the floor shudder. Out of the corner of my eye I saw a flicker of rapid motion, like an eyelid closing.
The rear door — the one that led out of the chamber in which we were standing — had just slammed shut.
Celestine fell forward. She had been standing in the gap.
‘No…’ she said, hitting the ground with a detectable thump.
‘Childe!’ I shouted, unnecessarily. ‘Stay where you are — something just happened.’
‘What?’
‘The door behind us closed on Celestine. She’s been injured…’
I was fearing the worst — that the door might have snipped off an arm or a leg as it closed — but it was, mercifully, not that serious. The door had damaged the thigh of her suit, grazing an inch of its armour away as it closed, but Celestine herself had not been injured. The damaged part was still airtight, and the suit’s mobility and critical systems remained unimpaired.
Already, in fact, the self-healing mechanisms were coming into play, repairing the wound.
She sat up on the ground. ‘I’m OK. The impact was hard, but I don’t think I’ve done any permanent damage.’
‘You sure?’ I said, offering her a hand.
‘Perfectly sure,’ she said, standing up without my assistance.
‘You were lucky,’ Trintignant said. ‘You were only partly blocking the door. Had that not been the case, I suspect your injuries would have been more interesting.’
‘What happened?’ Hirz asked.
‘Childe must have triggered it,’ Forqueray said. ‘As soon as he stepped into the other room, it closed the rear door.’ The Ultra stepped closer to the aperture. ‘What happened to my float-cam, Childe?’
‘I don’t know. It just isn’t here. There isn’t even a trace of debris, and there’s no sign of anything that could have destroyed it.’
The silence that followed was broken by Trintignant’s piping tones. ‘I believe this makes a queer kind of sense.’
‘You do, do you?’ I said.
‘Yes, my dear fellow. It is my suspicion that the Spire has been tolerating the drone until now — lulling us, if you will, into a false sense of security. Yet now the Spire has decreed that we must discard that particular mental crutch. It will no longer permit us to gain any knowledge of the contents of a room until one of us steps into it. And at that moment it will prevent any of us leaving until we have solved that problem.’
‘You mean it’s changing the rules as it goes along?’ Hirz asked.
The Doctor turned his exquisite silver mask towards her. ‘Which rules did you have in mind, Hirz?’
‘Don’t fuck with me, Doc. You know what I mean.’
Trintignant touched a finger to the chin of his helmet. ‘I confess I do not. Unless it is your contention that the Spire has at some point agreed to bind by a set of strictures, which I would ardently suggest is far from the case.’
‘No,’ I said. ‘Hirz is right, in one way. There have been rules. It’s clear that it won’t tolerate us inflicting physical harm against it. And it won’t allow us to enter a room until we’ve all stepped into the preceding one. I think those are pretty fundamental rules.’
‘Then what about the drone, and the door?’ asked Childe.
‘It’s like Trintignant said. It tolerated us playing outside the rules until now, but we shouldn’t have assumed that was always going to be the case.’
Hirz nodded. ‘Great. What else is it tolerating now?’
‘I don’t know.’ I managed a thin smile. ‘I suppose the only way to find out is to keep going.’
We passed through another eight rooms, taking between one and two hours to solve each.
There had been a couple of occasions when we had debated whether to continue, with Hirz usually the least keen of us, but so far the problems had not been insurmountably difficult. And we were making a kind of progress. Mostly the rooms were blank, but every now and then there was a narrow, trellised window, panelled in stained sheets of what was obviously a substance very much more resilient than glass or even diamond. Sometimes these windows opened only into gloomy interior spaces, but on one occasion we were able to look outside, able to sense some of the height we had attained. Forqueray, who had had been monitoring our journey with an inertial compass and gravitometer, confirmed that we had ascended at least fifteen vertical metres since the first chamber. That almost sounded impressive, until one considered the several hundred metres of Spire that undoubtedly lay above us. Another few hundred rooms, each posing a challenge more testing than the last?
And the doors were definitely getting smaller.
It was an effort to squeeze through now, and while the suits were able to reshape themselves to some extent, there was a limit to how compact they could become.
It had taken us sixteen hours to reach this point. At this rate it would take many days to get anywhere near the summit.
But none of us had imagined that this would be over quickly.
‘Tricky,’ Celestine said, after studying the latest puzzle for many minutes. ‘I think I see what’s going on here, but…’
Childe looked at her. ‘You think, or you know?’
‘I mean what I said. It’s not easy, you know. Would you rather I let someone else take first crack at it?’
I put a hand on Celestine’s arm and spoke to her privately. ‘Easy. He’s just anxious, that’s all.’
She brushed my hand away. ‘I didn’t ask you to defend me, Richard.’
‘I’m sorry. I didn’t mean—’
‘Never mind.’ Celestine switched off private mode and addressed the group. ‘I think these markings are shadows. Look.’
By now we had all become reasonably adept at drawing figures using our suits’ visualisation systems. These sketchy hallucinations could be painted on any surface, apparently visible to all.
