With Merrick's consent, and in secrecy, we enlarged every photograph of any value, but the quality of the originals defeated us. And we lacked concrete information as to how the journey could be made again. But of one thing I was fairly sure. The initial flight might have been to Mexico City, but the cave was not in Mexico at all. There was a map, yes, drawn with an unsteady hand in black ink on common modern parchment paper, but it gave no place names, only a diagram involving "The City" and the aforementioned Village One and Village Two. We had it copied for preservation's sake, as the parchment paper was badly damaged and torn at the edges. But it was hardly a significant clue.

It was tragic to read the enthusiastic letters which Michael had sent home.

I shall never forget the first letter he wrote to his mother after the discovery. The woman was very ill, and had only just learnt that her case was terminal, news which had reached Matthew somewhere along the route, though we had no indication of where precisely, and Matthew had begged her please to wait for him to come home. Indeed, it was on that account that he had cut the journey short, taking only some of the treasure, a great deal of which remained.

"If only you'd been with me," he wrote, or words to that effect.

And can you imagine me, your gangly and awkward son, plunging into the pure darkness of a ruined temple and finding these strange murals which defy classification? Not Maya, certainly not Olmec. But by and for whom? And in the very midst of this, my flashlight slips out of my hands as if someone snatched it from me. And darkness shrouds the most splendid and unusual paintings I've ever seen.

But no sooner had we left the temple, than we must climb the rocks beside the waterfall, with Cold Sandra and Honey leading the way. It was in back of the waterfall that we found the cave, though I suspect it might have been a tunnel, and there was no mistaking it because the mammoth volcanic boulders around it had been carved into a giant face with an open mouth.