Southtrap

'Who alerts who?'

'Boulder would contact the Regional Telecommunication Hub involved — that's South Africa. Then the wires would hum!'

The same thing applies to the balloon,' added T-shirt Jannie. 'We know the balloon will travel like smoke in the Westerlies. But if she suddenly started slowing before she reached her ceiling of twenty-five kilometres above the earth, we'd want to know why. Boulder would sound the alert. Come over here.'

He led me to the balloon. The envelope was spread but on the deck for checking like a huge parachute. At its base was a tiny aluminium box.

This was Jannie's scene. 'Bokkie's a marvel, but this instrument package is… is…' He indicated the box. 'Feel it.'

I weighed it in my hand. It was the size of a miniaturized transistor radio. 'It's incredible,' I said.

'Weighs about half a kilogram,' he told me. 'It's the sort of thing the Yanks use in their space probes. This isn't one of those zero pressure balloons the French and us are using for research in the stratosphere. They're huge and carry a scientific payload of about thirty kilograms. Their data is telemetred to earth in the fifteen MHz frequency and picked up in Reunion and Pretoria by special tracking stations. This is a little beauty which can be launched from a ship without special apparatus.'

Smit joined us. This Global Experiment is the biggest thing that's ever been undertaken weatherwise — there'll be detailed observation made for the first time of the entire atmosphere of the world and the surface of the Seven Seas.'

'Including the Southern Ocean,' I added.

They singled out the Southern Ocean specially,' said Smit.

Holdgate said from his comer, The way you lot go on, you'd think that meteorology was the only science in the world. Why, if we knew more about Prince Edward geologically we'd open up a new chapter in the history of the earth. It's one of the most important places for understanding the composition of the earth's upper mantle and the theory of continental drift and ocean floor spreading. The island's practically unexplored. The only work done was for a few days about ten years ago…'

I broke in. 'You may never get ashore, Doctor Hold-gate — let me warn you before you start raising your hopes. The Quest could lie off Cave Bay for a month without the opportunity.'

He brushed my cautions aside. 'Do you know the big cave?'

I sensed Wegger tighten up. His boredom during the discussion of the Bokkie project had vanished. He was staring keenly at Holdgate.

'No,' I replied. 'Or rather, I've only seen it through binoculars from about half a mile out to sea. The anchorage is very tricky and I couldn't get close. There's also a barrier of kelp between the anchorage and the cave. It didn't look much from the sea — just a huge hole in the cliffs about four metres in diameter, big rocks, no beach and some wiry-looking tussock grass here and there.'

'My theory is that the cave is a lava tunnel which goes right under the island,' said Holdgate in his lecturing manner. 'If it is, it's the only one so far as we know which belongs to the older period of volcanic activity on the island. When the volcano erupted originally it must have been like a blast furnace under the island and the gas pressure must have been colossal to blow out… anyway, I intend to explore the cave and find out.'

Wegger's voice sounded thick. 'You're wasting your time. There's nothing there. The cave stops after a short distance.'

Holdgate looked mulish. 'You're wrong. My information is that the cave goes deep, very deep. That's what the geologists reckoned who managed a few days on the island in the sixties. Anyway, how do you know anything about it?'

Wegger's damaged right talon-plucked at his karate-type blouse. 'I've been there,' he replied harshly. 'Years ago. Before your scientific pals. There's nothing except a few old dates Scratched on the walls by survivors of ships who sheltererd in the cave.'

The two of them seemed to be generating enough heat to re-kindle the fires of Prince Edward's dozen extinct volcanoes.

'Now get this clear,' I snapped at both of them. 'I don't give a damn whether Prince Edward's cave is or isn't the most fascinating place on the face of the earth, or whether it does or doesn't go under the island. But I'm not going to risk my ship for anyone's scientific hobby-horse — understood? I'm the person who's going to make the decision whether parties go ashore or not — whether it's to explore volcanoes, or look at the birds or any other bloody natural wonder. It'll depend entirely on the weather and on how I and I alone interpret the danger factor.'

The echoes of my broadside were still snarling in the 'tween decks beams that night when I was called to the scientists' sanctuary. The top-like head of the buoy glowed in the beam of my flashlight. Next to it was the shroud-like drogue, and the balloon with its aluminium instrument package.

Holdgate was there, too, lying strapped to the burial board.

This time he wasn't play-acting.

He had a knife in his throat.

CHAPTER TEN

The scrimshawed ivory handle stood out like an obscene white fang below the left point of his chin. His half-open jaw rested on one of its notches. The blade itself was lost in the ginger growth of his beard.

I knelt to examine him. The torch reflected a glimmer of unfocused eyes. Before I put my hand against his heart I knew he was dead. His skin was cool and clammy. He had been dead some time.

I directed the beam into his eyes, then at the knife again. There was surprisingly little blood. On the side away from me the knife handle was engraved. I scanned it more closely. The outline was unmistakable. It was a killer whale. The killer whale is the Southern Ocean's most feared and relentless killer.

'Petersen!'

It was Petersen who had burst into my cabin a few.minutes before — it already seemed like hours — and had stood swaying in the doorway. His face had been blanched and his eyes wide with horror. He had been violently, cruelly sick. I had grabbed hold of him and forced the rest of my nightcap brandy down his throat while he had hung, incoherent and half-fainting, in my grip. He had finally coughed out Holdgate's name and pointed aft. I had left him hanging over a chair and sprinted for the stern, telling him to follow. As I had cleared the superstructure, the cold wind had made me gasp.

'Petersen!'

He wasn't there. I straightened up and swung the flashlight round to find the light switches. Then I thought better of it. The murderer might be lurking somewhere. Even if he were not, to put the lights on would be to attract anyone who might be around. My first instinct was to bar anyone from seeing what lay there on the burial board.

I groped for the door. As I got there, the chilling implications of murder hit me: locks, fingerprints, door handles, keys, clues.

There was a sound on deck outside. I fell back, waited. I snapped the beam suddenly on to the face of the man in the doorway.

It was Petersen. He was swaying. I thought he was about to pass out again.

'Come in!' I ordered.

'Is… is…?' He coughed.

I kept the torch off Holdgate and snapped, 'He's dead. There's nothing we can do about that. But there's lots we can do about finding out who did it.' I found the switches. 'Listen, Petersen, before I put on these lights, get a grip of yourself. You're a ship's officer. Keep your eyes skinned. The killer could be around. No one is to know about this business — understood?'

'I understand.' His answer came from very far away.

I used my handkerchief to grip the key in case of fingerprints. We were still in darkness. Then I remembered something.

'Was this door open or shut when you found him?'

'That's why I came and looked in,' whispered Peter-sen. The door was slatting in the wind. So I came to see and…' In the dimness I could see that he was clamping his teeth into his knuckles to steady his jaw.