'Counter-espionage, by Jove! Counter-espionage! Spies and cloaks and daggers and beautiful blondes tucked away in the wardrobes — or wardroom, should I say. But why — why are you «here?» What do you — well, what «can» you want to see us about, Dr. Carpenter?'
'A small matter of murder,' I said.
'Murder!' Captain Folsom spoke for the first time since coming aboard ship, the voice issuing from that savagely burnt face no more than a strangled croak. 'Murder?'
'Two of the men lying up there now in the drift station lab were dead «before» the fire. They had been shot through the head. A third had been knifed. I would call that murder, wouldn't you?'
Jolly groped for the table and lowered himself shakily into his seat. The rest of them looked as if they were very glad that they were already sitting down.
'It seems too superfluous to add,' I said, adding it all the same, 'that the murderer is in this room now.'
You wouldn't have thought it, not to look at them. You could see at a glance that none of those high-minded citizens could possibly be a killer. They were as innocent as life's young morning, the whole lot of them, pure and white as the driven snow.
12
It would be an understatement to say that I had the attention of the company. Maybe had I been a two- headed visitor from outer space, or had been about to announce the result of a multimillion-pound sweepstake in which they held the only tickets, or was holding straws for them to pick to decide who should go before the firing squad — maybe then they might have given me an even more exclusive degree of concentration. But I doubt it. It wouldn't have been possible.
'If you'll bear with me,' I began, 'first of all, I'd like to give you a little lecture in camera optics, and don't ask me what the hell that has to do with murder: it's got everything to do with it, as you'll find out soon enough.
'Film emulsion and lens quality being equal, the clarity of detail in any photograph depends upon the focal length of the lens — that is, the distance between the lens and the film. As recently as fifteen years ago the maximum focal length of any camera outside an observatory was about fifty inches. Those were used in reconnaissance planes in the later stages of the second world war. A small suitcase lying on the ground would show up on a photograph taken from a height of ten miles, which was pretty good for those days.
'But the U. S. Army and Air Force wanted bigger and better aerial cameras, and the only way this could be done was by increasing the focal length of the lens. There was obviously a superficial limit to this length, because the Americans wanted this camera to fit into a plane — or an orbiting satellite — and if you wanted a camera with a focal length of, say, two hundred and fifty inches, it was obviously going to be quite impossible to install a twenty-foot camera pointing vertically downward in a plane or small satellite. But scientists came up with a new type of camera, using the folded-lens principle, where the light, instead of coming down a long, straight barrel, is bounced around a series of angled mirrored corners, which permits the focal length to be increased greatly without having to enlarge the camera itself. By 1950 they'd developed a hundred-inch focal-length lens. It was quite an improvement on the old world war two cameras, which could barely pick up a suitcase at ten miles. This one could pick up a cigarette pack at ten miles. Then, ten years later, came what they called the Perkin-Elmer Roti satellite missile tracker, with a focal length of five hundred inches — equivalent to a barrel-type camera forty feet long. This one could pick up a cube of sugar at ten miles.'
I looked inquiringly around the audience for signs of inattention. There were no signs of inattention. No lecturer ever had a keener audience than I had there.
'Three years later,' I went on, 'another American firm had developed this missile tracker into a fantastic camera that could be mounted in even a small-size satellite. Three years round-the-clock work to create this camera, but they thought it worth it. We don't know the focal length, it's never been revealed: we do know that, given the right 'atmospheric conditions, a white saucer on dark surface will show up clearly from three hundred miles up in space. This on a relatively tiny negative capable of almost infinite enlargement, for the scientists have also come up with a completely new film emulsion, still super-secret and a hundred times as sensitive as the finest films available on the commercial market today.
'This was to be fitted to the two-ton satellite the Americans called 'Samos III' — 'Samos' for 'Satellite and Missile Observation System.' It never was. This, the only camera of its kind in the world, vanished, hijacked in broad daylight, and, as we later learned, dismantled, flown from New York to Havana by a Polish jet-liner which had cleared for Miami and so avoided customs inspection.
'Four months ago this camera was launched in a Soviet satellite on a polar orbit, crossing the U.S. Middle West seven times a day. Those satellites can stay up indefinitely, but in just three days, with perfect weather conditions, the Soviets had all the pictures they ever wanted — pictures of every American missile-launching base west of the Mississippi. Every time this camera took a picture of a small section of the United States, another, smaller camera in the satellite, pointing vertically upward, took a fix on the stars. Then it was only a matter of checking map coordinates and they could have a Soviet intercontinental ballistics missile ranged in on every launching pad in America. But first they had to have the pictures.
'Radio transmission is no good, there's far too much quality and detail lost in the process — and you must remember that this was a relatively, tiny negative in the first place. So they had to have the actual films. There are two ways of doing this: bring the satellite back to earth, or have it eject a capsule with the films. The Americans, with their Discoverer tests, have perfected the art of using planes to snatch falling capsules from the sky. The Russians haven't, although we do know they have a technique for ejecting capsules should a satellite run amuck. So they had to bring the satellite down. They planned to bring it down some two hundred miles east of the Caspian. But something went wrong. Precisely what, we don't know, but our experts say that it could only have been due to the fact that the retro rockets on one side of the capsule failed to fire when given the radio signal to do so. You are beginning to understand, gentlemen?'
'We are beginning to understand indeed.' It was Jeremy who spoke, his voice very soft. 'The satellite took up a different orbit.'
'That's what happened. The rockets firing on one side didn't slow her up any that mattered: they just knocked her far off course. A new and wobbly orbit that passed through Alaska, south over the Pacific, across Grahamland in Antarctica and directly south of South America, up over Africa and western Europe, then around the North Pole in a shallow curve, maybe two hundred miles distant from it at the nearest point.
'Now, the only way the Russians could get the films was by ejecting the capsule, for with retro rockets firing on one side only, they knew that even if they did manage to slow up the satellite sufficiently for it to leave orbit, they had no idea where it would go. But the damnably awkward part of it from the Russians' viewpoint was that nowhere in its orbit of the earth did the satellite pass over the Soviet Union or any sphere of Communist influence whatsoever. Worse, ninety per cent of its travel was travel over open sea, and if they brought it down there they would never see their films again as the capsule is so heavily coated with aluminum and Pyroceram to withstand the heat of re-entry into the atmosphere that it was much heavier than water. And, as I said, they had never developed the American know-how of snatching falling capsules out of the air — and you will appreciate that they couldn't very well ask the Americans to do the job for them.
'So they decided to bring it down in the only safe place open to them — either the polar ice cap in the north, or the Antarctic in the south. You will remember, Captain, that I told you I had just returned from the Antarctic. The Russians have a couple of geophysical stations there, and, up until a few days ago, we thought that there was a fifty-fifty chance that the capsule might be brought down there. But we were wrong. Their nearest station in the Antarctic was three hundred miles from the path of orbit — and no field parties were stirring from home.'
'So they decided to bring it down in the vicinity of Drift Ice Station Zebra?' Jolly asked quietly. It was a sign of his perturbation that he didn't even call me 'old boy.'
'Drift Ice Station Zebra wasn't even in existence at the time the satellite' went haywire, although all preparations were complete. We had arranged for Canada to lend us a St. Lawrence ice breaker to set up the station, but the Russians, in a burst of friendly goodwill and international cooperation, offered us the atomic- powered «Lenin», the finest ice breaker in the world. They wanted to make good and sure that Zebra was set up in good time. It was. The eastwest drift of the ice cap was unusually slow this year, and almost eight weeks
