The man handed it to me. Without even turning my head to see who followed, I plunged into the darkness of the thicket and pulled the bushes aside from the mouth of the adit.

It was still open, safely shored and square, with the dry shaft leading level into the heart of the hill.

I had to bend my head now to get in under the lintel. I stooped and entered, with the torch held out in front of me.

*   *   *

I had remembered the cave as being huge, but had been prepared to find that this, like other childhood’s memories, was false. But it was bigger even than I remembered. Its dark emptiness was doubled in the great mirror of water that had spread till it covered all the floor save for a dry crescent of rock six paces deep, just inside the mouth of the adit. Into this great, still lake the jutting ribs of the cave walls ran like buttresses to meet the angle of their own reflections, then on down again into darkness. Somewhere deeper in the hill was the sound of water falling, but here nothing stirred the burnished surface. Where, before, trickles had run and dripped like leaking faucets, now every wall was curtained with a thin shining veil of damp which slid down imperceptibly to swell the pool.

I advanced to the edge, holding the torch high. The small light of the flame pushed the darkness back, a palpable darkness, deeper even than those dark nights where the black is thick as a wild beast’s pelt, and presses on you like a stifling blanket. A thousand facets of light glittered and flashed as the flames caught the sliding water. The air was still and cold and echoing with sounds like birdsong in a deep wood.

I could hear them scrambling along the adit after me. I thought quickly.

I could tell them the truth, coldly. I could take the torch and clamber up into the dark workings and point out faults which were giving way under the weight of the building work above. But I doubted if they would listen. Besides, as they kept saying, there was no time. The enemy was at the gates, and what Vortigern needed now was not logic and an engineer; he wanted magic, and something—anything—that promised quick safety, and kept his followers loyal. He himself might believe the voice of reason, but he could not afford to listen to it. My guess was that he would kill me first, and attempt to shore up the workings afterwards, probably with me in them. He would lose his workmen else.