Medusa

She scrambled up the steep bend, following the path across loose stone until it reached the base of the cliff where there were bushes growing, the entrance to the cave above screened by a dense thicket. Again there were indications of recent use, twigs snapped, small branches bent back, and in the black hole of the entrance itself the dry dust of the floor was scuffed by feet. ‘That’s not me,’ she said, flashing her torch. ‘I’ve only been into this cave once.’ Again there were skid marks as though a box had been dragged along the ground. ‘Watch the roof.’ She went on ahead of me, the height of the cave gradually lessening until I had to stoop. The sides of it were very smooth. ‘I’m not sure,’ her voice echoed back at me, ‘whether this has been scooped out by surface water making its way to the sea or by the sea itself.’

There were any number of caves around the coast, most of them well below sea level, some reached only by water-filled sumps or chimneys. Looking back at the moonlit half-circle of the entrance, I realised we were striking into the cliff at an oblique angle. We were also moving downwards. ‘You’ve got to remember,’ I said, ‘that when the ice-caps and the glaciers melted at the end of the last ice age the level of the sea rose very considerably.’

‘I know. The best of the caves are thirty to sixty feet down.’

‘Is that what your diving friend says?’

‘Bill Tanner? Yes. He says there’s a marvellous one by Arenal d’en Castell, a sort of blue grotto, enormous. He’s promised to take me down, sometime when I’m not fossicking around, as he calls it.’

I switched off my torch, looking back up the slope. The entrance was no longer visible, only the glimmer of moonlight on stone showing ghostly pale. The roof was getting very low, though at that point the walls had pulled back as though this were some sort of expansion chamber. Like the other caves in the Cales Coves area, the walls here were water-worn and the upper entrance high above sea level. It must have been formed at some period when the island’s rainfall was very much greater than it was now. The pounding of the sea so far below could never have done it by air pressure alone.

‘Here’s the roof fall.’ Petra’s voice came to me distorted and booming. ‘I’m just about there. But mind your head.’ And then I heard her swear.

‘What is it? Have you hurt yourself?’ I snapped my torch on, swinging it to send the beam lancing ahead down the tunnel.

‘No. Nothing like that.’ She was crouched down, her torch on the left-hand wall. In front of her the cave appeared to have collapsed, loose rock piled almost to the roof, rubble everywhere.

‘What is it then?’ I scrambled down the slope.

‘Look! It’s gone. The bastards have put their bloody shovels right across it. They’ve scraped it clean away. Why did they have to enlarge the hole?’ She was leaning forward, brushing at the rock face with her fingers, the fine limestone dust sifting on to the stone below and almost white in the torchlight. She sat back on her haunches, cursing softly under her breath. ‘If only I’d sent you a message and come straight back here and waited. When do you think they did it?’

She turned her torch on the fallen roof and the gap that showed between the broken rock and the rubble below was about three feet wide and not more than two feet at the highest point. There was air coming through it. I could feel it cool on my face and there was a smell of the sea. ‘I should have come back,’ she said again. ‘Knowing somebody had been working on this fall, I should have stayed here to explain to them how important that drawing was.’

I tried to tell her not to worry about it too much. ‘This is quite an extensive roof fall. Get this rubble shifted and you may find more drawings as you expose the rest of the cave walls.’ It wasn’t the cave drawing that interested me, though I realised the loss of it meant a lot to her, it was the fact that a passage had been cleared through the roof fall. It wasn’t only that I could smell salt water, I could hear it, the slop of wavelets on the rocks in the cove or against the base of the cliffs. ‘I’m going through,’ I said.

‘No.’ Her hand gripped my arm. ‘It’s dangerous.’

‘Don’t you want to know what’s the other side, why they’ve been digging away at this roof fall?’