'Is Bill ready?'

Diving in six fathoms – thirty-six feet – was going to be no problem to Bill, who was already kitted up in a wet suit and aqualung, and was dipping his mask into a bucket of sea water someone had hauled up on deck. He already had his orders and they were of the simplest. He was to take down a couple of sample bags and bring me back a little of anything he could see – I didn't expect nodules, but the cinder and shell-laden bottom material would be fascinating to me. I had expected him to take someone else down with him in the accepted buddy system, but he was scathing about it and said he preferred to dive alone.

'When you want a buddy most is on the surface,' he told me, overturning most of my accepted belief at a stroke. 'You get disorientated pretty fast down there, even in clear water like this, and half the time you're not in sight of one another.'

So we'd put the smaller dinghy into the water and it was from there that Bill would launch himself into the sea. 'It won't take long,' he'd promised Geordie, and I felt sure that we could be away in an hour or so.

As he prepared to climb down into the dinghy he paused, sniffing the air, and commented, 'Someone hasn't washed their socks lately.'

That was the thing that was niggling at my mind, and recognition brought a stronger sense of unease. There was a heavy, sulphurous smell in the air. Geordie and I looked at each other and he said, 'Sulphur, Mike?'

'Well, this is a known volcanic region,' I said. 'I suppose it's always a bit niffy here.'

Ian spoke, pointing out to the horizon. 'You can almost see it in the air, skipper.' The sky low down was brightening into the dawn but there was a strange yellow tinge to it.

Bill was in the dinghy now, with Jim and Rex Larkin to row it a few yards off from Esmerelda. He sat on the thwart, gave the traditional thumbs-up sign as he made a final adjustment to his mask, and toppled backwards into the sea. For a few moments we could see his body sinking away from the dinghy. He had just disappeared when Geordie said hoarsely, 'Bill -stop him! Don't let him dive!'

It was too late. Several heads turned to stare at Geordie, who had suddenly gone ashen and was wrestling with the wheel, and at the same moment there was a babble of talk from the men at the bows and railings.

'For God's sake, we're spinning!' Geordie said, and I saw then what he meant.

Esmerelda was boxing the compass! Her bows swept slowly over the horizon as she twirled in a complete circle, not very fast, but with a suggestion of power in the colossal eddy that had her in its grip. And at the same time I saw a rising column of mist, darkening even as it rose, that appeared as if by magic out of the sea half a mile or so away from us. There were shouts of alarm from people, and I clung to a staunchion to steady myself as we spun about.

Almost as soon as it happened it had ceased, and Esmerelda was rocking tipsily, but steadying up again with the billowing steamy cloud ahead to starboard. I saw other little eddies appear and vanish on the sea's disturbed surface, and the smell of sulphur was suddenly pungent. I heard Geordie shouting but for the moment a ringing in my ears made it sound very faint and distant, and I shook my head to clear it.

'Ian! This is bloody dicey, but we've got to get an anchor down! We'll lose the dinghy and Bill both if we start shifting.'

I heard the anchor cable rattle out of the hawse pipe almost as he spoke, tethering Esmerelda to the shallow bottom. I could guess how reluctant Geordie would be to sacrifice his precious mobility at that moment, but it was of course essential to keep station. The dinghy rocked heavily and I saw a line being thrown to her, presumably to keep her in contact with us.

Campbell's body lurched into mine as we swung round the anchor cable, and Geordie called, 'Not enough – she'll swing into the dinghy! We'll have to get Bill up fast!' But he had gone down free-style, without a line, and there didn't seem to be any way to do it. I saw that some of the crew were swinging out the motor launch, and guessed that Geordie would use it to take up the dinghy crew into a more seaworthy craft, leaving the smaller boat in tow.

'How long will he stay down?' I asked, staring over the side. The whole surface of the water was rippling and beginning to chop.

'Not long at all,' Geordie said tensely. 'The moment he breaks surface we'll have him up out of there. With any luck there'll be enough disturbance down below to get him up quickly. Thank God it's shallow – at least he won't have a decompression problem.'

'What's happening?' Campbell's voice sounded as if he'd asked that question several times already.

I said, 'Wait a moment – I'll explain later.' I was staring at the column rising from the sea as if mesmerized. There was hardly any noise but the column blackened steadily, with a white nimbus around it, almost like the smoke of an oily fire, and I knew without a doubt that if there was no underwater disturbance to bring Bill to the surface, there was another phenomenon that would work as well – the sea would be rising in temperature, not to boiling point, at least not here, but several degrees above its normal state. I knew that I was looking at the beginning of an underwater volcanic eruption, and my heart was thudding as if my chest would burst open.

Geordie guessed it too, and a ripple of awareness ran through the crew. Campbell's mouth hung open and his hand fell away from my arm. Eyes were scanning the water near us, looking anxiously for our diver's reappearance, and glances over our shoulders kept us in touch with the increasing activity away on the horizon. Esmerelda was still rocking a little roughly but there was no feeling of instability about her. Something broke surface not far from the dinghy.

'There he is!' called Danny, pointing.

We saw the two men still in the dinghy pulling Bill in over the thwarts, the motor launch waiting off to take her in tow back to the ship, when there was a totally unexpected interruption.

Taffy Morgan shouted, 'Ship on the starboard beam!'

I spun round incredulously and pounded across the deck, colliding with someone on the way. Out of the smoke and steam that drifted across the sea ahead of us, half shielding her until the last possible moment, the bulk of Sirena came bearing down upon us.

Her yards were bare and she was pounding towards us full tilt under power. I could see figures on deck, many of them, and the lift of her bow wave as she approached.

'Goddam it! We're trussed up here for the slaughter,' Campbell said in vicious unbelief.

Geordie ran up the deck. 'Slip that flaming cable!' he bawled.

But there wasn't enough time. Sirena was on us, slewing and with her speed falling off at the last possible moment to lay alongside us with a minimum of seamanship, relying totally on surprise to aid her terrible attack. She didn't quite make the turn and her bowsprit stabbed at us like a monstrous rapier. There was an almighty crash and Esmerelda shuddered violently and moved bodily sideways in the water.

I was thrown against Geordie and we both went down in a tangle of arms and legs. I scrambled to my feet, all the breath knocked out of my body, and saw hazily that Esmerelda's yardarm was locked in Sirena's shrouds.

Ramirez had rammed us. The chaos was indescribable.

There was a roar of angry voices and a flood of men poured across the deck from Sirena, and I saw the flash of knives in the enveloping glow of that fantastic yellow light.* Chapter Eight** 1*

It was a short fight and a bitter one.

In the fraction of a second before they were on to us I saw Campbell's incredulous face, his mouth open in surprise. Then Geordie roared, 'Stand together, lads!' and I was grappling with a hefty brute who wielded a long and wickedly gleaming knife.