The possibility of escape suddenly seemed a lot less likely. Behind us were Caraway and Pockmark – although they looked a lot different now.

If I say they were mere shadows of themselves you’ll get the idea. They looked like shreds of drifting smoke, and I could see right through them. They seemed to have no legs or feet – just ragged strands of darkness that trailed slightly above the ground. Even their faces looked thin and insubstantial – except for their eyes, which glowed like hot coals.

They looked a lot more like my idea of ghosts than they did when they were aboard the ship. Not very nice at all, I can tell you. The pirates seemed unable to speak in this form – they could only make unpleasant hissing noises like a threatening snake. But with those glowing eyes trained on us, they made it pretty clear by pointing at the map, then straight ahead, then at the map again, that they expected us to get on with finding the treasure.

So with Henry leading the way we entered the jungle. The light was greenish and the air warm and sticky; the undergrowth on both sides of the narrow trail was virtually impenetrable. Together with the bugs that were soon biting everyone and the ominous rustling sounds, the place was far from wonderful. I started to wish I was back on the ghost ship.

The cursed pirates followed us, as if they were afraid we would steal their treasure – though I’m not sure what they thought we would do with it.

Most of the time the path, turning and twisting, climbed steadily. We had waded through thick undergrowth for about two hours, I guessed, before Henry stopped and pointed to the big red X on the map.

“We’re almost there,” he said, striding on and emerging into an open space.

We carried on, awash with sweat by now, tired and bitten to death. From there the path climbed a few hundred metres further to an opening in the rockface.

Henry consulted the map again. “It looks like the treasure is hidden in that cave,” he said.

The ghostly pirates were clearly excited, waving us on and hissing a lot as we shuffled towards the entrance of the cave, which was really little more than a crevice between two big rocks. Henry scavenged some bits of dead tree root and lengths of creeper vine, tying them together to make a rough torch. Then he produced a box of matches that – don’t ask me how – he had not only managed to hang onto since our capture but which, even more amazingly, still worked!

The torch smoked a lot and didn’t smell that great but it gave us enough light to see by as we entered the cave.

We all squeezed in. Henry raised the torch and my eyes widened. By its jumping, flickering light I saw that we were not alone.

Well, in a manner of speaking, anyway – because the two people already occupying the cave were not only dead but, unlike Blackbeard’s crew, looked as if they’d been that way for some time. Their skeletons lay propped up against the back wall of the cave. I realised they were both clutching cutlasses, the blades of which stuck out of both bodies around the area of the rib cage.

I shuddered – if I had been frightened by the fake skeletons at the museum, these terrified me. Henry however marched over and took a really close look at the two bodies.

“I’ll bet these are the ones who buried the treasure,” he said. “Perhaps they fell out afterwards and killed each other.”

I imagined a grizzly image of the two men struggling desperately, stabbing each other at the same moment. But Henry had already moved on to examining the floor of the cave.

“This bit has definitely been disturbed,” he said. “I think we should dig here.”

If it hadn’t been for the fact that we were prisoners of the infamous pirate Blackbeard and that there were two scary dead men hounding us, this could have been pretty cool. As it was, we were all hot, tired and nervous – not to mention itchy from all the insect bites.

We dug in silence. The dazed prisoners barely spoke any more anyway. Several blisters later, our spades hit something hard.

“Aha!” Henry remarked. I was just glad we might soon get to stop – I was exhausted.

It took a few minutes to uncover the lid of a wooden chest and dig around it enough to drag it out onto the floor of the cave.

Of course it was locked – and of course Henry wanted to smash the lock and take a look inside.

I had my doubts that was a good idea, but Mr Stevens was as excited as he could possibly be, under the circumstances. “Open it, Henry,” he said.

Henry hesitated for a moment. Then he said, “Well, they did give us these sacks, so they must intend us to fill them with whatever’s inside! He grinned. “I for one am not going to do all this digging and not know what’s in there. It might be full of rocks!”

He had a point. As no one had anything more to say, Henry gave the chest a thump with his spade. The old wood groaned and he hit it again. This time the bit around the lock split open with a crack. Henry lifted the lid and we craned to look inside. My heart pounded with excitement. Pirate treasure! Even the dazed prisoners peered in and Mr Stevens looked as if he was going to faint from excitement.

Needless to say the chest was not full of rocks. It was, in fact, bulging with coins, jewels and some old plates and cups – all made of the same shiny stuff. No one said anything. We all just stared. I think we might have stood there for a long time, but eventually Henry slammed down the lid of the chest with a bang that made everyone jump.

“OK,” he said. “Let’s get this outside. Our floaty friends will be wondering what we’re up to.”

It was only then that I realised the two cursed pirates had not come into the cave with us. Had something about the place kept them out? Maybe they had once known the skeletal sailors? Maybe it reminded them that they were actually dead? In any case, they were waiting for us as we hauled the heavy chest outside. Their red eyes seemed to gleam all the brighter and the hissing noises got louder, which seemed as near as they could get to cheering.

Gold is heavy stuff, and I was glad of the sacks we had been given before we left the Destiny’s Wyrd so that we could spread the load between us. We emptied the chest and filled the sacks as fast as we could.

While everyone was busy, Henry pulled me to one side.

“Listen, Dolf,” he said. “On the way back to the ship we’re going to make a break for it.”

“But they’ll see us, won’t they?” I exclaimed. “And if they do they’ll leave us here alone without food and water!”

“We’re not going to be left behind,” said Henry. “And I don’t think we’re alone, anyway.”

“What!” I said, probably too loudly, because Henry shushed me.

“Didn’t you notice all that rustling in the underbrush?” Henry asked. I had, of course, but I’d been thinking of large scary animals.

“You mean someone’s following us?”

Henry nodded. “Almost since we left the beach. I thought it was monkeys or something at first, but there was a glint of something metallic – and to my best knowledge birds or animals don’t carry anything made of metal.”

“So what’s the plan?” I asked, resignedly.

“Once we get back into the jungle, fall behind a bit. As soon as the others are out of sight we’ll get off the path.”

I thought of the thick undergrowth, where anything could be lurking. But I knew it was no use arguing with Henry; he had that determined look he gets when we are up to our eyes in trouble and he’s thought of a way out.

Once the treasure had been transferred into bulging sacks the cursed pirates made it clear they expected us to get a move on and head back to the ship. There was a bit of grumbling among the adults, which showed they were actually beginning to wake up – maybe because they were no longer on the ship. I heard Cyrus Firestone say something about ‘slave labour’ but the two ghostly shades flew around us in circles, glaring and hissing and pointing until finally everyone swung a sack over his or her shoulder and began to stumble back down the slope towards the beach and the waiting ghost ship.

Fortunately for Henry’s plan, Caraway and his chum Pockmark were so eager to show off the haul (as if they had done all the work instead of hanging about outside the cave!) that they went ahead. I suppose they thought there wasn’t anywhere much for us to go so they weren’t worried.

They didn’t know Henry Hunter. As soon as we were deeply into the jungle Henry dropped back, allowing the rest of our little party to get ahead. At a bend in the path he slipped sideways into the heavy foliage, beckoning me to follow. In fact, the undergrowth wasn’t as impenetrable as it looked, and within minutes we were several feet from the path and well hidden. Henry stopped to wait for me and we both dropped our sacks, which were a bit lighter than everyone else’s thanks to the fact that we were smaller and younger.

“So what happens now?” I hissed, as quietly as I could.

“We wait,” said Henry cheerfully, slapping another thirsty bug out of existence. “For whoever it is that’s been following us to put in an appearance.”

We didn’t have to wait long. After several minutes of listening to the ‘zing’ of insects and the far-off chatter of birds in the canopy of the jungle, there was a rustling sound off to one side and, while I was still wondering what we would do if it turned out to be something big and nasty with razor-sharp claws and pointy teeth, the bushes parted and a face looked through at us.

I let out an involuntary yell and once again Henry had to shush me. To be fair, even HH looked pretty amazed to see who it was that had been following us. Probably the last person in the world we could have expected – considering that the last time we had seen him he had been falling backwards off the deck of the Moby Dick into the depths of the ocean.