Disclaimer: anything you recognise does not belong to me, but to the Mouse House.

Author's note: this is a mad, mad fic which sprang into being from pretty much nowhere. It features several original characters, who are archaeologists. I'm not an archaeologist, and my knowledge of that science is limited to bits of internet research and that wonderful programme, Time Team. So I've done some guesswork and some fudging, and I hope any real archaeologists out there will forgive me and maybe offer constructive criticism? Comments from readers always very gratefully received!

----

We had not expected to find an island. There was nothing on the chart – nothing but miles of blue Caribbean Sea – but yet the island was indisputably there, looming out of the water. We anchored our yacht off the rocky cliffs and lowered one of the speedboats to investigate further.

Nobody said anything as the boat crept into the largest of several cave entrances. A flashlight bounced off the walls of the cave and reflected in the dark water, and the light landed eventually on a little sandy beach. We landed, pulling up the boat.

That was when Simon exclaimed.

"Gold!" he said, pointing his light into the water. "Look!"

We looked, following the flashlight beam down into the depths. Simon was right. The seabed was covered in gold – coins, perhaps, though the detail had long since been worn away by the relentless tide. Jerry, the expedition leader, bent down and scooped up a dripping handful.

"17th century," he said, after a brief examination. "At a guess." He looked up, his eyes bright as the coins in his hand. "What have we found?"

We moved quickly now, down dark tunnels. I don't think any of us were sure what we were looking for, not exactly. Simon, our geologist, led the way. I was at the back of the group, and so it was that when the others all stopped abruptly I cannoned into them.

"What is it?"

Jerry merely moved aside, so that I could see, and like the others I stood agape at the sight before us. A cave, lit by a sunbeam shafting down on to a mountain of treasure. Coins, ornaments, jewels, precious stones, piled haphazardly in heaps.

"Bloody hell," Jerry said, eventually.

"That's one way of putting it." We fanned out into the cave, stooping to trickle the treasure through our fingers.

"Bones!" said Toni. She picked up what looked like a femur. "Old bones."

Simon straightened from a partially-submerged heap. "There's an entire skeleton here, Tone."

We hastened across to him, and gathered around the skeleton. The clothes had disintegrated years before, but bits of metal – buckles, rings, a necklace – hung on the bones yet. The ribs were cracked over the heart, and delving between them Toni pulled out a deformed wad of lead.

"He was shot. Once. Point-blank range."

"I wonder who he was?" I said, aloud. The others turned to me. Simon was smiling.

"Ever the people person, Becks," he said.

"I'm an anthropologist," I pointed out, reasonably enough. "How old do you think he might me, Toni?"

She was crouched by the skeleton, examining it with gloved hands. "Three centuries? Judging by the buckles, and the state of the bones. I'll have to do some proper tests back on board – can we take it back?" she asked, looking up at Jerry.

"Have to get permission from the authorities first," he said. "But yeah, sure." He pointed. "Look, the guy had a cutlass too."

"There must have been a fight," I said, picturing it in my mind. "If he was shot, someone shot him." I began to pick around, searching for more clues. There were another two swords by the water's edge, rather rusty.

"What's in that chest?" Simon asked, pointing. I followed his finger to the top of the steepest pile of treasure, where a heavy stone chest sat illuminated by the sun. We climbed, with difficulty, up to it, and stood looking down at it for a moment.

The chest was elaborately carved with symbols that, at first glance, appeared to be of South American Indian origin – probably Aztec, I thought, running a careful finger along the carvings. A thick lid covered it, and a layer of dust covered that.

"Shall we?" said Simon, less interested than I in the decorations.

I nodded, and together we pushed the lid open.

We gaped. Underneath the stone and the dust, the gold shone brilliantly. A chest full of gold coins, each emblazoned with a grinning skull. I ran a hand over the surface.

"Aztec," I said, sure now. "Aztec gold."

"How much?" Simon questioned, his fingers hovering as if to take a coin.

"Who knows?" My fingers hit something that wasn't metal, and I picked out a slender knife. "Oh."

Together we examined the tool. It appeared to be made of bone, ancient and fragile, and the edge was darkened with an old stain.

"Blood," said Simon, his voice thrilling with excitement.

"I think …" I frowned down at the chest. "I think we should leave this as it is until we can come back."

Simon folded his arms. "Why, Rebecca?"

"I don't know." I shrugged. "I just … I have a feeling. Anyway, we need to find out who this place belongs to, and get permission to work here. We can't just go lifting Aztec gold willy-nilly."

"Becks is right," Jerry said, coming up behind Simon. "As you know, Murphy. Let's get some shots and then let's go and report this place."

We spent an hour or so carefully taking photographs, trying not to disturb anything further, and recording what we'd found. Toni and I estimated there were five or six skeletons in the cave, but only one of them was intact. The rest were scattered, in pieces amongst the treasure. As for the treasure itself, it ranged from the chest of Aztec gold to pieces of china and ornaments clearly of European origin; most of it evidently chosen for its gaudiness rather than pure value. I was hopeful that it would turn out to be a pirate or privateer's hoard, one of the many undiscovered treasure troves of the Caribbean.

Back on the yacht, we were all in high spirits. Jerry sat down immediately to send an email to our base in Kingston, and Simon broached a bottle of rum. "Just in case we have found a pirate's cave!" he said, grinning. "Seems suitable to celebrate with rum."

We drank, and talked of the unexpected island and the miraculous find. That night I dreamt of gold and silver and jewels, of flickering torchlight on bright metal, and of blood on bone.

In Kingston, we reported the find to the authorities and settled impatiently to waiting for their response. We wanted to go back and investigate the site properly, with dating tools and permission to take bones and other items from the cave. But such bureaucracy takes time in any country, and still more in laid-back Jamaica, and so we were forced to kill time planning the proposed expedition.

It was three days later, as Toni and I sat in a beachfront restaurant eating lunch and discussing the possible provenance of the skeletons in the cave, that things took a turn towards the bizarre. We had a sketched plan of the cave laid out on the table, weighed down with salt cellars and a Caribbean guide book, and were little concerned with those around us. It was only when the waiter arrived with our salads and I leaned back that I noticed the man watching us.

In hindsight, it was absurd not to have noticed him before. Even in colourful Jamaica, he stood out, dressed as he was in a tattered turquoise shirt with his braided and beaded hair hanging down to his shoulders. He was smoking comfortably, his legs crossed in front of him; and he was watching Toni and I with an alert, intelligent gaze.

I looked away, not wanting to stare, yet from then on I was conscious of his eyes on our backs. He waited until we had finished our meal and the waiter had cleared the plates before standing, stubbing out his cigarette and coming over to us.

"Ladies."

We looked up. He smiled, a smile full of gold teeth.

"Ladies, I couldn't help but notice the map you had out earlier."

Toni glanced at me, her expression asking clearly what I thought we should do about the stranger. I shrugged.

"Plan of a cave, or somesuch, wasn't it?" His hand sketched a circle in the air.

"That's right." I looked up at him from behind my sunglasses. "Can we help you?"

"I'd like a look, if it ain't too much trouble."

Unrolling the plan, Toni spread it out on the table, and the man thanked her with a nod that was almost a bow, and bent over it. He looked at it intently for a moment, a little half-smile hovering on his lips, and nodded.

"Isla de Muerte."

"I'm sorry?"

He looked back at me with very direct dark eyes. "Isla de Muerte, love. The island that can't be found, except by them that know where to find it." A pause. "But you found it?"

Toni sat back in her seat. "We came across an island that wasn't on our map. Are you saying you know of it?"

"I know of it." The stranger did not sound particularly happy about the fact. "Tell me, ladies – you didn't by any chance see a stone chest, in that cave, did you?"

"The one with Aztec carvings?"

"Aye, that one." His gaze bore into mine. "Please tell me you didn't take a coin from that chest? That you left it as it was?"

I shook my head. "We left it." I frowned at him. "Why? Who are you? How do you know about this place – it's the biggest historical find in the Caribbean for decades! It needs properly investigating. But nobody else knows about it?"

The man smiled again, and pulled up a chair. Sitting down without asking our permission, he leant his elbows on the chair arms and put his fingertips together.

"It's like this," he began.