Despite the complexity of my thoughts, or maybe because of it, I felt my eyes growing heavy. I closed them again and drifted into a half-waking dream of looking down on the valley of the Skylake from above as if I were a bird flying over it, or a spirit-form with waking eyes. But instead of a lake, there was a flat pale-grey stone oval alongside a cluster of low, square grey buildings with shining windows that showed only a reflection of the world outside, rather than what lay within. I heard a distant roar that caused the earth to tremble and I looked up to see something long and narrow and immense flying high overhead; a giant dart of metal with a tail of flame. Then there was another sound from below and I looked down to see that the flat grey oval had split through the centre along a perfect seam and each side was drawing back into the earth to reveal the dark, gaping crater beneath it.

Deep down in the shadows I saw something glimmer and then there was a humming sound and several enormous metal darts like the one that had flown overhead rose slowly out of the darkness and into the sunlight. There was a long, high-pitched whine and then an earsplitting explosion of noise and all of the metal darts shot into the air.

Missiles, I thought, remembering the name the teknoguilder Pavo had used for the deadly flying weapons of the Beforetimers; the kind that could be directed in their course and in their destination by their human controller. Was I seeing the past or a glimpse of a future in which the weapons controlled by the Balance of Terror computer were evoked? Either way it would mean that the weapons were not in one single location, as I had always supposed. If that were so, perhaps that was why my quest had always focused on Sentinel and the need to prevent it from activating the Balance of Terror computers, which controlled the mechanism that would trigger the weapons. In truth I had never understood why Sentinel was not in direct control of the weaponmachines, but it would make a good deal more sense if the Balance of Terror weapons were in a whole lot of different locations. Certainly I had come to understand that there was a distance between the two computers, but I had assumed that all of the weapons must be in the same place as the BOT computers.